So I should develop my creative app as a native app because it needs hardware access and browsers don't support that. And browsers shouldn't need to support hardware access because app developers should just build native apps.

Maybe you should try my app. (try it at https://pianop.ly/grid.html ... it works ok in Firefox in "player piano" mode)

All the other stuff other than MIDI, browsers support just fine. (including one critical thing, ability to embed, synch with and overlay on top of youtube videos)

Browsers support an awful lot of things, because people want that. I can tell you with regard to my app, I highly doubt a single developer could build it as a native app that was available to as many people.