Some sources point to difficulties which may destroy the bridge, so the Wikipedia article on the Crimean Bridge e.g. has:
"The geology of the Kerch Strait is difficult: it has a tectonic fault, and the bedrock is covered by a 60 m (197 ft) layer of silt.[44] About 70 mud volcanoes have been found in the area of the strait.[44] More than 7,000 piles support the bridges; these piles have been driven up to 91 m (300 ft) beneath the water surface.[44] Some of the piles are at an angle to make the structure more stable during earthquakes.[44]
Some experts have expressed doubts that the construction is durable, given the tectonic and sea current conditions in the strait.[44][45]
Pollock, Emily (6 July 2018), Europe’s Longest Bridge Spans Troubled Waters, Engineering.com, archived from the original on 13 October 2018
Kerch Strait Bridge may collapse at any time – expert, UNIAN, 12 October 2018