A 'fun' fact from the graphtreon data: they are currently earning 8.4k, which is 600 bucks less than just six months ago, and that's not going to improve in the near future. So fear not, patrons keep penalizing them for not releasing an update.
Now, more financial details: Patreon takes at least an 8% of that income, plus other exchange fees that I won't take into account. Then there's VAT, which is a whopping 21% in Spain that Patreon will take from them and give to the Spanish tax authorities - and considering devs' job doesn't really need many inputs, they can't compensate that amount with the VAT they pay for those inputs. That means that they currently have a net revenue of less than 6k per month. Now, they are self-employed, so with their gross income they are forced to pay about 350 bucks each to the Spanish Healthcare, and we are down to 5.3k per month. Of course, they still need to face the Personal Income Tax for their annual revenue, which could mean that they'd need to put aside about the 40% of their income. So in the end they are currently earning about 3.2k, maybe 3.8k per month if they can take advantage of some tax benefits due to them being a family. A family of 4 members, living in Spain. Even if my maths are off for 1k, they are not getting rich with this game, that's for sure.