Kurzgesagt make high quality animated videos and seem to be doing quite well. 13 million subscribers on the English channel alone. All of that despite only releasing about one video a month.
I doubt they make much YouTube revenue, they also have 14,856 patrons on Patreon. Probably the only reason that it's worthwhile for them to continue to make such high quality animated videos.
CGP Grey is another animator. Looking at his Patreon, he's current at over $40k/month. Considering he's mentioned having a staff now, I'm sure that gets split between his entire project, but it still seems like it's significantly funded by supporters over ad revenue.
To be fair though, the animation part of the content is only a minor part of it. The educational and entertainment value of what's actually said is much more important.