Kurzgesagt went hugely downhill, I'll still watch the occasional video from them, but most of what they do now is super speculative tenuous science with 5 min of sponsored content.
I remember way back in the day I enjoyed laci green for her sex ed content, but she just suddenly went super right wing.
I remember back in high school I watched Sexplanations a lot. Introduced me to a lot of concepts I've been using to this day. I think I stopped watching her because I outgrew her channel.