I’ve run a battle gauntlet completely online and that worked great, but from feedback nobody in that particular group enjoyed the short roleplay parts that had to happen online before the gauntlet started. Also online play definitly requires more prep work by the DM (imho), especially as you can’t easily do improv maps if what you are doing requires a map (I think it’s easier to do that in person, but I’m willing to concede that point )
playing in multiple campaigns with discord as voicecom and roll20 or FGU for characters and battlemap…
online play makes some things smoother (as long as the DM knows how to use the tools of their choice, which can take quite some time) - mostly battles, or a turn based exploration sequence - while it does hamper roleplay in my experience, mostly because it is next to impossible to have more than 1 person talking and still understand anything, which happens at the table quite regularly without problems.
personally I prefer roll20 out of these options, but FGU is technically a bit better for people with weak internet (once all the ressources are loaded).
As for voice quality: I think discord is superior to zoom (especially if someone used nitro to boost the server you’re using, but even without simply because it allows users to actually adjust settings way more granulary),
As for video quality: Zoom is a bit better here, but pretty much all groups I’m in don’t use video.
My conclusion: online play is better than no play, but in person is the superior roleplay experience