I have the impression that being “good” at the game wasn’t even a concern back then. I remember a lot of players being completely unbothered about their own character levels and wealth. Players were busy building communities and driven by small and personal achievements. Sometime I wish gaming had remained niche and never reached the masses. The early 00s was such a sweet spot.
I made games primarily for Windows which we also compiled for Linux. It is mostly input/output stuff, aka hardware issues. That is, audio issues, input issues, storage issues, dependency issues. Modern game engine mostly handle the rest. It wasn’t such a big deal to fix, but most gamedev lacked experience with Linux, and most projects are already over budget and late, so fixing Linux for an extra 2-5% of sales didn’t make much sense at small scale. Proton kind off fixed all of this tho.