I've now been through three different online group classes (not just lessons). One class was originally in-person before the virus outbreak, another was something more casual available through work, and the last purely online through some kind of EU integration fund.
The volume problem: It does exist to some degree. Unfortunately there are people who are loud talkers or shout into the microphone. You turn up the volume for some listening exercise recording that's too quiet, and of course somebody then decides to unmute their microphone and start talking over it, splitting your eardrums in the process.
I know there has to be some option to deal with it though. Apparently Windows 10 has something built-in called "Loudness Equalization" under <em>Sound Control Panel > Playback tab > [Your speaker] > Properties > Enhancements tab</em>. I'm not sure if that will help to be honest, since I only just recently read about it, but it seems promising. In any case, I know streamers generally use so-called compressors or limiters to try and keep a balanced audio volume, so it's not like this should be some great unsolvable technical problem. Or maybe there's some better headset?
Other issues:
<ul><li>When everybody else except the teacher turns their video camera off, so you feel like you're interacting with a class full of disembodied voices.</li><li>I don't have a printer at home, so it's less convenient to do certain learning exercises with some PDF files - although there is some software that lets you annotate or edit them.</li><li>Terrible audio quality - doesn't happen all the time, but it's still not ideal when it does.</li><li>The problem of "wait, where are we?". Sometimes teachers fly all over the place with lesson material and you're not sure which and what part of the five files they sent that day we're suddenly on now.</li></ul>
It ought to be better, but unfortunately the only advantage of online group lessons for me so far is that I don't have to travel anywhere to get to them.