For sure. That the MU80 (or later) is the best way to hear MIDI game music from the 90s and early 2000s should take nothing away from the passionate musicians and coders who did brilliant (and sometimes unnatural) things to extract better results from the innately weaker hardware of early PC sound cards (Sound Blaster et al).

Yamaha's many various OPL chips were based on cost and feature reduced versions of the FM synthesis engine in Yamaha's professional standalone music synthesizers. These chips powered not only PC sound cards but also a huge variety of 80s and 90s arcade machines, game consoles and home computers (https://en.wikipedia.org/wiki/Yamaha_OPL).

It's fascinating to explore the evolution of the OPL technology as this "lower cost, lower end" alternative to pro gear gained in sophistication and power culminating in 1994's OPL4 chip (aka YMF278) and its even more capable cousin the YMF292 used in the Sega Saturn console. These chips had impressive synthesis power for their consumer console/sound card price point. By the late 90s onboard music synthesis in sound cards, consoles and arcade machines began dying due to increasing storage and CPU power permitting playback and mixing of fully sampled music tracks. By the early 2000s the only remaining consumer application of Yamaha's powerful onboard synthesis chips was for generating ringtones in mobile phones. It's kind of sad such a rich musical legacy ended up playing 5 second mono tracks on half-inch speakers (although those mobile phone chips probably made more money for Yamaha than all their pro music gear til that point combined).

Here are two good links from my retro research bookmarks: The best rundown on the genealogy and capabilities of Yamaha's FM sound chips I've seen: https://gist.github.com/bryc/e85315f758ff3eced19d2d4fdeef01c.... And a collection of very impressive OPL4 music tracks: https://www.youtube.com/watch?v=zqD52xioky4.