Genesis games had better OST. The sound chip on the SNES is probably better though , most games on it had a more orchestral feel. Something the genesis couldnt do.
https://www.youtube.com/watch?v=2MbyPP9Wahc
https://www.youtube.com/watch?v=FQtIZR467Zo
https://www.youtube.com/watch?v=qUmXhuma2XY
https://www.youtube.com/watch?v=JIw6qetdhVk
This is coming out of a real Sega Genesis. This is what the Genesis sounds like when it's not limited by the small storage size of commercial cartridges.
The Genesis could produce all kinds of music.
EDIT: As comparison, here is the same track. One limited to the 8 MB of the standard Pier Solar cartridge, then followed up with the "unlimited" space the PCM CD affords
https://www.youtube.com/watch?v=dudBuSkj_QY
Pier Solar is the only game that pushes the Genesis' audio hardware to the very limits, which makes sense since Sega audio god TmEE worked on the game.
Outside of Demoscene and Pier Solar, people honestly have no idea the sorts of amazing things the Genesis YM2612 could produce.