That's about 10x more that I'd consider reasonable for what is effectly hosting a static website and bulletin board. I think we've all just had our expectations blown out of the water by Steam (and the subsequent app stores).
Patreon gets to take the money they take because they've found a good niche, not because their website can do something that all websites have been able to do since the 1990s.
I personally think they take too much for what they provide. That's all. I am very happy they exist, though, because otherwise everyone would just be chasing the algorithm.
That is describing most money-making websites in existence