I've entertained the idea before, but as someone who hates their voice and can barely hold a conversation with people I've known for decades, I always just dismiss it as "sure would be nice, but it'll never happen".
I wouldn't even know what to talk about. Until you've got a decent number of viewer to have an active chat (which may not ever happen), you're essentially talking to yourself out loud for hours, right? I just can't imagine being able to do that.
Yes. You will absolutely be shouldering most of the talking.
However.
I think relying too much on chat reaction as a beginner is where a lot of newbie vtubers get discouraged and down on themselves. There has to be a fine balance of giving enough attention to your chatters and making the content and your "performance" fun/interesting enough for them to stay.
Never forget that as a vtuber you can definitely detach yourself a lot more than you think and get absorbed into the keyfabe--it gives me the nostalgic feeling of the reason people fled to the old net or mmos: to become someone different than they are irl without shame or insecurities boggling you down. I think this is what I like most about it--virtual larp-- bring a cute anime character is the best part. So own it!
It's been a good learning experience BEING the vtuber if anything else, and it's a LOT of hard work in terms of maintaining energy and learning improvisation on the fly. I completely understand how many burn out, even just 2-3 hours of streaming is a lot.
But here's what I've got so far if you're thinking of going for it:
Playing games and making commentary to yourself is definitely a way to make up for a slower chat. Playing games is also the hardest type of content to make more interesting because if the viewers don't care for the game, the less likely they'll stay. It's also tough to juggle focusing on the game and conversing with chat. Definitely stick to playing games you enjoy (or hate ) so that you can talk more about it, and infectiously get your chat involved too.
When it comes to doing zatsudan, deep dives, or focused/planned content, this is where things can really shine--it helps to have a reaction from a chat but you can circumvent a lack thereof by also leaving less time for dead air and having content to review in depth. Reading weird archived posts and bringing up obscure facts and questions is a good way to get a ride out of yourself and chat too. Think of it as pre-recording for a YT video; chat being there is a bonus!
Not to mention, the model IS important--if you have the privilege of owning an L2d model, figure out your toggles and animate yourself as much as possible. The better you are at piloting the "mech," the more people will stay just to see your reactions too. Sometimes streams can just be talking about your day or a traumatic childhood experience and making your model dramatically react to it. Working with assets and coming up with skits is good too.
Side note: I empathize with shy/awkward moots. I've found that maybe I'm more schizo or something bc I don't mind talking to myself even when there's slow days oops. They really weren't joking when they said a vtuber actually is some level of mentally ill... incredible...