The game is hidden behind a paywall, only subscribers have access to it, it is not accessible to the public, plus each tier is often linked to certain rewards depending on how much you pay. It is not a tip or some charity money when certain content and even the game itself are only accessible for those who pay.
I also support two youtubers/streamers from my country. In that case, I'm donating because I want them to keep doing what they do, but their content is free. That's a donation; the other thing is not a donation, it is a quid pro quo.
This guy has 1,300 patrons; the most usual tier is €5. With a rough estimation of € 6,000 a month since that's the most common tier (it's probably more actually), and if he indeed lives in Spain, it would blow your mind to know how much that is compared to certain professions. That's about the salary of a Spanish Supreme Court judge, to name just one.