Music has to make specific use of the OPL3 for it to make a difference. Otherwise it just sounds exactly like OPL2.

With OPL3 you get twice the number of channels, stereo (full pan L/R), and 4-operator mode.

To get an idea of what a difference it makes, listen to the OPL2 version of Running from Evil from Doom 2, compared to Kvee's OPL3 cover of it:

https://www.youtube.com/watch?v=Cd5C4iqjqnY&t=15s

https://www.youtube.com/watch?v=EmA9R8bt0vE&ab_channel=kvee

Now of course some of the difference here comes from the fact that Bobby Prince (afaik) did not make any custom instruments, but kvee did. You can get a lot out of OPL chips if you are willing to painstakingly create good-sounding instruments.

There are some games that use stereo OPL3 soundtracks. The Lost Vikings and Black Thorne are a couple examples.

Dune also has a unique-sounding soundtrack with the Adlib Gold, which uses an OPL3 chip.

Cybersphere requires a sound card with OPL3 chip as it uses the additional features both sound effects and music.

Some Interplay games like Descent and Stonekeep have stereo music when OPL3 is used.