Well, Liberapay is for donations only, hence it is not a true alternative to Patreon and such. Also, you still have to pay the processing fees which, they say, should be below 5% on average.
Nonetheless, it is pretty well-made and needed, especially since they care about internationalization.
Patreon is largely that function for people. The ability to just get donations existed long before. A tool to combine donations with access to exclusive stuff is the main focus of Patreon.
Personally, I see paywall-service as unfortunate because paywalls shouldn't exist. We need to find solutions (like patronage not tied to paywalls) to fund creative works that aren't restricted or freemium or whatever.
The freerider-dilemma is a real thing. Even when it works in some cases (Wikipedia has large enough audience to get by on donations even when the percentage that donates is tiny), those are the exception.
Hence the efforts to build better coordination models (such as https://snowdrift.coop is doing).
Because in principle, all the same amount of resources could fund the same work and yet a far greater audience could get that much greater value without paywalls.
Paywalls are a compromise that dramatically reduces the overall benefit a work has in order to get over the freerider problem that public goods face.
Basically: the PAY part isn't the problem, the WALL part is.
I mean that it's not an absolutely set necessary conclusion that stuff can't get funded equally well without paywalls. It might require different cultural norms, different ways to organize people or many other solutions, but IN PRINCIPLE the resources are available and could be available without paywalls.
And other than securing funding, there's nothing else positive about paywalls (although I'll admit there's potential arguments around ideas like people appreciating things more when they have to pay for them — things that still don't anywhere near outweigh all the negatives that paywalls have)
Nonetheless, it is pretty well-made and needed, especially since they care about internationalization.