I think Jack at Patreon fundamentally misunderstood the nature of the relationship between patron and creator. A lot of patrons feel like their payment is a donation instead of paying a subscription or water bill. Yes, some patrons+creators have a quid-pro-quo arrangement where payments unlocks content or extra services. However, many payments are just "appreciation" type of money. That is a fragile relationship and it was wrong to tamper with it by charging extra fees to the patron.
Jack was/is a creator himself so he should have known this dynamic and therefore predicted the bad outcome ahead of time.
Ideally, when you start a multi-sided platform, you want to get the economics correct from the very beginning so you can leave it unchanged. (E.g. Apple iTunes charges 30% since 2008 and it's stayed that way.) However, if you have to readjust the percentages, it's preferable to take it out on the sellers' side and not the buyers' side. When ebay started, the fees for sellers were ~3.25%. Over the last 10 years, it has crept up in increments to ~10%. All of those price increases were absorbed by the sellers.
If Patreon needs more than 5% to make the numbers work for a sustainable business, they need to take it from the creators and not the patrons. Patreon was riding on the "good will" of patrons making voluntary payments. It was a terrible miscalculation to destroy that good will and nickel & dime patrons with extra fees.