I used Patreon since it was a convenient way to 1) just get some money flowing without having to deal with all of the complexities of integrating a payment processor, e.g. without having to waste what little time I have on things like taxes (Patreon automatically handles the VAT), 2) I don't necessarily run this as I would run an actual business and most of the features are completely free, so it kinda fits Patreon's model of "supporting a creator" instead of your normal SaaS model of completely paywalling everything and giving you only a two weeks' worth of trial use, and 3) most people have already heard of Patreon, so when you're brand new and just starting out it's somewhat less sketchy than asking for people's credit card numbers directly.

In the long-term I'll probably switch to using Stripe or something along those lines (while still keeping the option to use Patreon for those who prefer it), but at this income level it's not really worth my time.

So to answer your question, I think that whether using Patreon is a good way to finance your side projects depends on what those projects are, and on what exactly you goals are.

If you're trying to run a profitable business then what I'm doing is not a good example of what you should do. It might be totally obvious, but the more you give out for free and the more you rely on voluntary Patreon-like donations the less money you'll make. I know of other apps (using a fully paywalled financing model) in this space which have less users than I have and yet they're already hiring other people to work on them, while I can't even pay myself a livable wage to make this a full time job, never mind even thinking about paying someone else to help me out.