What is the status of Mitvah for typical jews?

Question

As we know many mitvah are no longer done. Stoning is one example. Burning a city when someone introduce Shiva, Jesus or other deity is another example.

Some rabbi even prohibits polygamy while not prohibited in Torah. That seems like adding commandments there.

So is Mitvah no longer obligatory for jews?

War are no longer followed by forced marriage and massacre of all males. Palestinians are not warned first to evic or be subjects. They were not massacred too once the war is over.

What is the story? How do jews rationalize the obvious facts that they no longer perform many mitvahs?

Are jews, like christians, cherry pick mitvah they wanna do? Are we all the same. We do what we like and kind of like the idea that we can blame others for not doing something?

Note: Some of the comment says that those mitvahs are not done because it's no longer do able

Actually there are many samples where mitvah is doable. The torah doesn't say anything about Sanhedrin having to okay things first before stoning people. In fact, some extra judicial killing such as those done to Pinehas is praised in Torah.

Another area where Jews have been far more liberal than their ancestors is when it comes to mamzer

Modern investigations into mamzer status

Today, civil divorce and remarriage without a get (Jewish Bill of Divorce) has become commonplace, while Jewish marriage is popular even among the less-religious. This situation has created a crisis threatening to create a large subclass of mamzer individuals ineligible to marry other Jews, threatening to thus divide the Jewish people. Decision-makers have approached the problem in two ways. Orthodox Judaism

The principal approach in Orthodox Judaism is to require strict evidentiary standards for mamzer status, sufficiently strict that proof of the existence of mamzer status is hard to develop and generally does not arise. Typically it is impossible to prove either that a prior marriage ever existed, or that a child was born of relations outside that marriage. Rabbis always allow the suspect child the benefit of the doubt in this matter. This usually leads to the conclusion that at the time of a person's birth, their parents were married or that the person is the son of a man who was married to his mother.

Nowadays, there is no way a mamzer can't be found out. We got paternity tests. However, elaborate "rules" are created to make it almost impossible for anyone to be declared a mamzer. In one hand, the reason why this is done is very reasonable, and in fact, that's where the problem is, it's too reasonable. On the other hand, this is an obvious case where political expediency pretty much thrump explicit commandment.

Moreover,

The category of mamzer has no role in Reform Judaism or Reconstructionist Judaism, as these more liberal branches regard it as an archaism inconsistent with contemporary ethical behaviour.

Looks like Mitvah that's too politically incorrect will just be gone for "some reason".

Another sample is proof in court. Torah requires people to be condemned if and only if 2 or more witnesses come up. I am sure jews and pretty much the rest of the world rely more on forensic evidences instead of 2 witnesses nowadays.

I am not saying that it's a bad thing. But to say that it's what the Torah means seems to be quite contrived. Either Torah is bad, or Torah is super good but jews don't do it anymore. One thing for sure is, some mitvahs are simply not done.

Answer 1

I will try to answer specific things you say one at a time -- that doesn't mean that they are connected or make for a good question, but here I go (apologies in advance for the lack of formatting -- anyone better equipped is invited to edit this and make it presentable an help me figure out why, even though in my text, I have numbered the OP points sequentially, in the preview, they are all numbered "1"):

1. As we know many mitvah are no longer done. Stoning is one example. Burning a city when someone introduce Shiva, Jesus or other deity is another example.

   1a. Mitzvot which cannot be followed because of a current situation (the lack of a temple or a proper religious court) are not applied. This does not lower their status as commandments but recognizes that they cannot be applied currently. We learn them in the expectation that in the future, they will be applicable again.

2. Some rabbi even prohibits polygamy while not prohibited in Torah. That seems like adding commandments there.

   2a. There are categories of takanot, enactments which do create a fence around the torah law so we do not get too close to breaking the torah based commandements. Read this for more.

3. War are no longer followed by forced marriage and massacre of all males. Palestinians are not warned first to evic or be subjects. They were not massacred too once the war is over.

   3a. The biblical laws of war and warfare are complex and do not apply now -- not that the laws are less obligatory, but we are not in a position to follow them. But there was no law to massacre people once a war is over, anyway.

4. Actually there are many samples where mitvah is doable. The torah doesn't say anything about Sanhedrin having to okay things first before stoning people. In fact, some extra judicial killing such as those done to Pinehas is praised in Torah.

   4a. Before the Sanhedrin can enact a death penalty, a warning is needed. The laws of the warning are complex and not every action requires this particular warning before any penalty can be exacted. To reduce it to an absolute "the torah doesn;t say" disregards that Jewish law is based on significantly more than a literal reading of the Torah text.

5. Nowadays, there is no way a mamzer can't be found out. We got paternity tests. However, elaborate "rules" are created to make it almost impossible for anyone to be declared a mamzer.

   5a. Ignoring the reference to Reform Jewish practice as it is irrelevant to a discussion of the applicability of divine Torah-sourced law, you miss another part of the quote, "Typically it is impossible to prove either that a prior marriage ever existed, or that a child was born of relations outside that marriage. Rabbis always allow the suspect child the benefit of the doubt in this matter." The laws of mamzeirut are confusing because they require an investigation into certain issues of parentage -- they are not a simple matter of who the father is. If you reduce Jewish law to a single statement then it seems that we are avoiding its application. If you study it in all its glory over 20 years then you understand that it is a dynamic and complex construct based in specific logic and source material and flowing and shifting within certain bounds.

6. I am sure jews and pretty much the rest of the world rely more on forensic evidences instead of 2 witnesses nowadays.

   6a. What you are sure of and what constitutes acceptable proof within the bounds of a religious court are clearly 2 different things. Your sensibility does not drive halacha any more than mine does.

7. But to say that it's what the Torah means seems to be quite contrived. Either Torah is bad, or Torah is super good but jews don't do it anymore.

   7a. To say that something is what the torah means indicates deep study and existence within a tradition, not that anything is contrived (which would indicate a complete and baseless innovation). Your next dichotomy is a false one. The torah is, I guess, "super good" and Jews DO do it nowadays. It is just something different from what you understand. Instead of assuming that your view defines torah and its observance, and you are the arbiter, maybe you should admit a bit of ignorance and assume that those WITHIN the system have a better sense of what it means to observe it.