You're absolutely right. There was a time period when I uploaded the same volume of videos on YouTube (back when I first started that channel) and participated in a Vidtember (1 video a day for 30 days in September, plus a few extra). Even the the revenue was bumped up slightly, it didn't really move the needle much.

Also, like you said, I have over 100 videos on that channel, all still generating views. So actually, the last 30 days only saw me uploading 2-3 videos, a huge portion of the views came from old videos.
Most people don't upload 'evergreen' stuff though, so they get the initial views, and that's it, apart from the trickle 10 - 20 extra views in the video's lifetime.

It's not really scientific, for sure, but I think it demonstrates how an absolute beginner can earn a LOT more potentially on DTube than on YouTube (who wont even allow any monetisation at present).