I wonder what value gpl even has in a world where i can trivially reimplement whatever a company builds on a permissive license and does not share. I see still

I wonder what value gpl even has in a world where i can trivially reimplement whatever a company builds on a permissive license and does not share. I see still a place for things that are low level, algo heavy, real world test heavy and critical eg. kernel, cryptography, storage engine, filesystems all the rest of userland and web not so much