I finally figured out how to get bluetooth headsets to work correctly on my desktop: output to 3.5mm, 3.5mm to dedicated bluetooth transmitter.

Throw hardware at the software problem, because software absolutely cannot be trusted not to foul this up. Not Windows, not linux, not pipewire, not pulse, none of it. Evidently not mac either, though I've personally never had trouble with bluetooth on mac. Bluetooth is 23 years old and its flagship application is still completely broken across huge swaths of the client/server compatibility matrix.

Asking the real questions here.

I finally gave up on using an XPS15 with Ubuntu because I could not get over the fact it cannot do high quality bi-direction bluetooth audio.

Edit: Looks like it does offer some improvments over pulseaudio: https://www.redpill-linpro.com/techblog/2021/05/31/better-bl....