My only criticism is the subscription fee instead of a one off charge for the full set of features. I would like a lot of them but I don't need cloud sync or another ongoing cost to worry about.
Lemmy doesn't. The app might. I don't use sync but if I'm an app developer I could make money plugging advertisements into my app. If I design the UI well enough, and make the ads unobtrusive, I might just make enough money and not piss anyone off.