I tried Patreon early one, like when they first started up. I didn't find it useful at all. Despite alerting all my readers about the Patreon site, few were willing to log onto an unknown site just to see what I had available (SOL readers are, in general, a pretty conservative bunch when it comes to signing into unknown sites). I'm told the site has become much more accessible, but as far as I can see, that just means you can now charge for page hits, rather than actual chapters written, which seems to be entirely missing the point of readers paying you to write, instead they're paying you to take them out of their way, subject them to abuse ads, and then leave in disgust without purchasing anything but you still make money.
However, a few people here have claimed to make substantial money (of course, someone else here at one time claimed they were making over 100K writing short porn novels of 5K to 10K using Amazon Prime, so who knows which are legitimate claims and which are only ego driven claims).
If you self-publish, you're only adding to the amount of work you have to do for little money, as there's a host of things you have to learn, navigate and manage. The idea behind Patreon is that you simply set up a 'contribution' structure with various rewards, and then readers pay you to write, NOTHING else. Thus you don't have to create and pay for your own website, you don't have to deal with formatting, creating epubs, or even worry overly much about the proper grammar (if your readers don't quit paying because of the typos).
For me, I've got a nice system set up releasing a couple books a year, so I'm not going to toss all of that aside and ask my readers to learn an entirely new system to support me—even if it may earn a little more money, as it's yet another money-sink.
If others find it useful, then more power to them, but so far, they seem more interested in getting anyone at all to visit their sites (where they serve as the author's clickbait mice). Also, I see NO way for an author to build a fanbase and reach new customers using Patreon, as few people seem to go there seeking stories, everyone goes there simply to support one particular person (usually a well-known band or best-selling author who's decided to ditch their publisher). In other words, they bring their audience with them, rather than building an audience over time.