This one dude has made this app for years and constantly updates it, fixes things, is responsive, and makes a great app. He's now been more loyal to his users longer than Reddit has, and I personally have used his app daily for 13 years.
Yeah, I'll happily pay for it.
FOSS is great but it doesn't pay the rent people, this guy is doing this mostly as his main gig. This isn't some huge corpo, it's one guy who makes his living building the app he loves. I'm sure he'd love to make it FOSS if he didn't have to pay bills on anything.