> If you aren’t familiar, look up Tsar Bomba on youtube and witness how terrifyingly destructive a 50 megaton warhead is

Tsar Bomba was a one-off experiment – and one designed for some level of psychological intimidation that you appear to have fallen for. No nuclear-armed country today maintains 50-megaton warheads for actual use against an adversary. Instead, planning involves use of a larger number of smaller warheads, and that is already enough to be worried about.