I agree it is on the user, but at the same time it is why I cancelled all of my Patreons. I was supporting so many creators it was easy for some to slip through the cracks that were no longer producing content, which did happen, especially when supporting them on lower tiers. I have a difficult time supporting a service that doesn't do anything about inactive creators.You apparently haven't read what Sumodeine themselves has said on the matter or perhaps you've forgotten:
So I would cut them some slack. They have been very transparent about time updates take them, that they cannot switch back to monthly if they change it, and that people should feel free to pause or drop if they want. Continuing to get billed monthly is 100% on the supporters anyway, but especially with the pains the developer has taken to make sure people are aware of the situation.
While yes it is on the user, there should also be some ownership from Patreon that at minimum sends a reminder that so and so hasn't posted anything in so long would you like to continue supporting them. Patreon has no incentive to do this since they take a cut of your contributions so why should they care if the creator quits producing any form of content.
In the past I even came across Royal Road authors that hadn't posted anything on Patreon or Royal Road in years, 2019 iirc, but had left comments previously hinting that if they picked up enough supporters they would finish the story. Not surprisingly they still had a bunch of supporters bringing in a nice chunk of money monthly even though they hadn't posted anything anywhere since.