The thing is that "the web" doesn't make sense as a platform for audio applications when to build upon it you need to throw away realtime safe subroutines.

Realtime audio rendering is a soft realtime problem. If the web audio APIs don't have methods for guaranteeing deadlines for rendering audio, it's only possible to build toy audio applications.

I'm aware of things like bandlab and such. They're still toys and too limited for serious work, where the money is.