You are laboring under a misunderstanding that most non-chemists have when it pertains to chemistry. You are unaware of the absolutely massive scale of tinyness that things are in.
Let's say you go to the sea and fetch a glass of water. Scoop it up. Now, you decide to have a contest with your friend. You have a magical bag that can contain anything in whatever amounts.
So you set off trying empty the water glass, one molecule at the time...
...and your friend sets off trying to empty the oceans of the world with one glass of water at the time.
You keep the same pace, the number of glass or molecule per minite.
You will lose, and with eons upon eons. You will not finish before the universe dies, though your friend migh.. In a $20$ cl glass of water there will be approx $4$ moles of water which is, if I typed it correctly, about $24920000000000000000000000$ molecules
Boiling water, purifying it, cleaning, scrubbing, leaching - none of these create pure water without contaminants. There is only a question of how many contaminants you can handle. 1 per 10000 or 1 per 10000000 makes the difference
Boiling water for 10 minutes brings the number of organic still living beings in the water down to a level where it does not harm your body. (normally - there are some parasites more durable than others - and harmful prions will be unaffected). It will still contain dead organic beings, mucus, shit, piss, toxic metals, harmful toxins - but in quantities your body can handle.
As long as tap water is measurably drinkable (potable, from french) the water works doesn't really care about the level of contaminant (of course they do, but if it is drinkable, it is drinkable, and the bar is set very low for that)
So no, boiling water is not strictly necessary as long as the level of contaminant is below whatever level of that contaminant is perceived as safe. And making the water chemically pure, as in totally free, of that contaminant requires a lot more than boiling, and is rarely done - and if you want water that clean you usually make it from it's constituent atoms or distill it repeatedly.
Don't be afraid of minute quantities of contaminants - you have been exposed to them since birth. Fun fact, if your eyes sting when swimming in a public swimming pool, it is likely ammonia (di) chloride, which is likely from urine. Enjoy!
just because you are obsessed with mucus, you just prove my point that was based uponassertions dictated by exhaustion :). – Jan 09 '20 at 08:11