> This sort of stuff is actually doable just with just video chat and OBS.

If what each person is hearing is 100-400ms delayed from what each person is producing, how can they possibly mutually react or even get their music in time? If B plays in time with what they hear from C, C hears what B did 200-800ms later - that's far too much and will sound terrible.

Jamming would seem to require incredibly low latency audio just for the rhythm to work between two performers.