As the title of the post asks: "I don't know who the Web Audio API is designed for".
The high-level nodes are not featureful enough for professional audio production, and too slow and underspecified for game engines like FMOD / Wwise.
The low-level bits fall somewhere between impractical, deprecated, and useless.
Who is it designed for?
Plug a few oscillators into each other and you have an FM synth. Feed delays into each other, etc, etc. You can do that in a few lines of code with no dependencies.
To me, that's a huge potential audience.
If you want a array of samples and depend on dozens of JS libs for functionality, well, I'm sure the AudioWorkers will catch up eventually.
As far as potential audience, in the time I've spent lurking in the Web Audio community, it seems like developers fall into one of two camps: 1) building toy projects for their own edification/learning, and happy to have the Web Audio API 2) trying to build a serious product (DAW, game, whatever) and super frustrated with the API. It seems pretty clear to me that end-users would be much better off if camp 2 had a good low-level API to work with.. camp 1 is not making much that gets used by end-users.
> It's not "serious business" but this is the browser after all.
Modern JS performance is actually quite good, and WebAssembly is only going to make it better. I think you underestimate the potential of audio processing in the browser.
> It's like a modular synthesiser.
I own hardware modular synths, and I built a proof-of-concept modular synth environment using the Web Audio API (https://github.com/rsimmons/plinth). The API makes it hard to build even simple things like well-behaved envelope generators or pitch quantizers. So even if you viewed the API as a sort of code-level modular synth environment, it's pretty unsuited to anything beyond trivial use cases.
The browser-based experimental/modular audio stuff that has any traction (e.g. https://github.com/charlieroberts) doesn't use the built-in nodes for these reasons.
Not game developers, not professional audio production people. It's... not an answer I was expecting, but I suppose it's valid.
This answer would have made sense to me circa 2003, but I cannot fathom it today. The web started as "let's put academic papers online". It moved to "let's put magazines online" with some modest interactivity via forms.
But we've spent the last 10 or 15 years turning the web into a "you can do anything" platform. There's been huge progress in interactivity and visuals. There's no a priori reason audio should lag so far behind.
