I'd agree and disagree. The quality has gone up quite a bit in my opinion (way better quests and not just again and again buying stuff with money, better animations and even better ones are to come, more details in every imaginable way, more and different interactions etc.) but when it comes to speed there's not much that can be done without sacrificing some of its uniqueness. The game is good because DC is drawing it and because of all those small interactions druing streams etc. which give a lot of creative and input. It's like comissioning a picture from a world class painter, you are paying a lot of money because he's making it and you wouldn't pay that money if someone else did it. Since there's only so much that DC can draw the natrual limits are obvious. I mean, he hired a background artist for the future and the animations are outsourced now but that's likely how far we'll get - no matter if the game makes 25.000 a month or 100.000 a month.
Last but not least, it's not like DC is demanding more money or promising to work a lot faster. The last development goal on patreon was set at 25.000 and all he's getting now is additional money.
I'd chalk that up to more or less him going full time.
Most projects, if not all, that are art intensive have multiple artists. To be frank his art isn't ridiculously unique that no one could copy it and he (DC) reuses poses/outlines for pretty much everything.
It's interesting that you bring up the stream. While it's undoubtedly great for engagement, it is an absolutely terrible way to develop a game. I've basically learned he does very little pre-planning, almost solely relies on viewers to make decisions (which affect game design and further bottlenecks code), and makes tasks that should take him 15-30 mins into 2 hrs. When he actually works he is incredibly quick.
I didn't say he was, I'm actually quite impressed that this has managed that much. Plus DC is doing what he wants and getting paid for it which not many people can say that.
The problem is you are getting to the point where a good chunk of people are going to scratch their heads and go something isn't quite right. He has made additional goals for extra help. You can safely assume that *should* help development. If people reach the aforementioned conclusion or lose interest (aka lose faith) money will be pulled.
The real kicker is that DC stated in one of his recent streams that he expects this to take another two years.