I know of:

CGP Grey and Kurzgesagt, who left the platform around the time the Curiosity Stream partnership began. Remaining creators have said the reason for their departure was basically that those two wanted to use Standard/Nebula as a way to leech off of other creators.

Jill Bearup who was removed after it was discovered she had made some transphobic comments.

Second Thought/First Thought, the main reason I’m making this post, because just yesterday I noticed that he was missing. It seems he was removed for his stance against the Israeli genocide against Palestinians.

Anyone know of any other creators who have left?