I didn’t bother watching any of his videos all the way through but I took a peek at the channel just to see what he’s content looks like. Seems like a decent and organized layout. You can tell he’s had time to develop his workflow and setup since he produces courses outside of YouTube.
Other than that, I don’t see why he cares about your opinion of YouTube. If he’s followed you or seen any of your recent content he should be able to understand your point of view without bringing up your mental state. The only thing about the comment that rubs off the wrong way is it’s very obvious he hasn’t watched much of your recent content without skipping around. I don’t get why he still looks at your new content now if it’s not that kind of content he likes anymore. Sounds like another victim of the YouTube clickbait addiction I guess. So much hate.