If YouTubers feeling burn-out made the changes they wanted to make, without telling anyone they were going to do it, the vast majority of their users probably wouldn't even notice.
Most peoples YouTube subscriptions feed is full of way more videos than they actually watch anyway.
Not saying there's anything wrong with making a video about it, I just think they care a lot more about it than their users do.
If you have a normal job you get feedback from your boss about your performance. If you do YouTube you get money from google but that has little relationship to how your users feel about your content.
I bet it's kind of like if you had a boss who stood over your desk all day looking directly at you but never saying a word.
You'd keep working harder and harder until burnout.