Comment by n_ary

Actually, here in my corner of EU, only the prominent big tech backed well documented and battle tested tools are most marketable skills. So, React, 50 new jobs, but you worked with Svelte/Solidjs, what is that? Java/PHP/Python/Ruby/JS, adequate jobs. Go/Rust/Zig/Crystal/Nim, what are these? While Go has some popularity in recent years and I can spot Rust once in a blue moon. Anything involving requiring near metal work is always C/C++.

Availability of documentation and tooling, widespread adaptation and access to already-trained-at-someone-else's-dime possibility is deemed safe for hiring decision. Sometimes, the narrow tech is spotted in the wild, but it was mostly some senior/staff engineer wanted to experiment something which became part of production because management saw no issue, will sometimes open some doors for practitioners of those stack but the probability is akin to getting hit by lightning strike.