Top tier game orgs are often large enough to have good people write their own library with the correct compromises. They also tend to need micro performance improvements enough to be worth it.
Yeah, EA open sourced their STL, although now that C++23 is supported (aside from on MSVC? Still not flat_map there?!?) there is some replication in the STL.
Not uncommon for audio companies to also write their own containers and internal STL for ex. plugins as well.