(Biggest culprits are Discourse forums.. which is a shame b/c I really like the platform)
I recently quit Firefox on Linux (they no longer support ALSA and require PulseAudio for sound). I used to think FF was a memory hog. Moved to Vivalidi (Chrome based). Consumes more memory and I'm sure it has a memory leak. On FF I would have ~ 30-60 tabs open. On Vivaldi it's 10-20. I have to close Vivaldi every few days to reclaim the memory.
Pulseaudio is sold as easier to manage, but for me it simply wasn't.
The assumption is that people are running systemd, and Pulseaudio presumably works well with that. But I'm not on systemd. If my distribution had a simple way of running pulseaudio and have it work more or less right out of the box, I'd go for it. But it doesn't.
They stopped supporting it because no developer stepped up to support it - that's all. Apparently the Pulseaudio API is straightforward for developers, whereas dealing with ALSA directly is not.