I am not the person who said "C++ has rotted their brain". I have not expressed a similar sentiment. I have never said that "borrow checker fixes all", in fact I said that it will not magically fix everything.

And if I want a bug-free code, I will use same tool as ever: my brain

Is your brain infallible?

The strategy is not to 100% eliminate every bug in existence or theory, bugs are inevitable. The strategy is Swiss cheese security.

Something is better than nothing. Therefore (brain + something) > (brain + nothing). As long as "something" works to prevent bugs, to any extent, it will result in fewer bugs.