There do seem to be others. The author of Vue.js seems to be doing ok as well:

https://www.patreon.com/evanyou/overview

And yep, I definitely agree. The long term sustainability of projects via Patreon clearly hasn't been established yet.

But, at least some _are+ actually now making decent money, so we can find out how sustainable things are over time.

Hopefully it mostly goes well, but yeah... it's unproven thus far. ;)