It's probably not a big source of their profit, and certainly a competitor can live without it. But as both a consumer and creator it's the only model I'm interested in. It really aligns everyone's incentives.
> I am not trying to copy Patreon. I am merely implementing the general idea of selling your digital content online. That's all.
You should stop posting, honestly. Either you tried to gather interest for your project by posting in a Patreon thread, or you've realized how little you actually know and you are backtracking.
Best to cut your losses, revisit what you are working on, make sure you have a clear path and you've verified it's what customers want, and build something you can show before talking about it.
This was you in the original post. If you consider Patreon a competitor, then you need to understand their business model far better than you apparently do. You don't need to copy them, but you do need to understand them. You cannot compete with an established company that you have given zero effort to understand.
The fact that you're having such a hard time understanding the difference between researching your competition and copying them is further proof that you aren't ready to be running a startup—you have a lot to learn about business before you're going to get anywhere. If you're dead set on continuing, it would be a good idea to learn a bit of humility and consider that maybe, just maybe, the dozen-or-so people on a startup forum telling you that you're wrong might know something you don't.