But Chrome for Android didn't come out until 2012 and Chris Rogers started the Web Audio work in 2009. I think someone would have had to have been exceptionally farsighted to think "Android's audio stack is going to suck for several years so we need to design around that now".

At that point in time, though, you could be forgiven with "Sheesh. Javascript is so painfully slow that nobody will ever pass PCM samples around in it."

So, at every point in time up to and including now, you've always got something resisting low-latency PCM. Android is just the latest reason.

Side note: it looks like Chris Rogers bowed out of Web Audio about 2012/2013 timeframe.

You couldn't really, since AudioData worked pretty well.

Also, it was obvious JS perf would get better and better.

Ah, good point. I should have checked better on things before commenting!