I would personally say you're pretty safe to sell the Series S and get a PS5.
Right now the PS5 honestly doesn't have that many exclusives, the big ones I'd say are Demon's Souls, God of War Ragnarok, and Horizon Forbidden West.
For a heavy gamer I'd say it isn't worth it, they'd blow through those in a couple of weeks.
For someone playing only a few hours a week though, these titles should hold you over until more releases like Hogwarts and FF7R2 as you'd mentioned, as well as FF16.
If you can afford it and you want to play, I say go for it. You gotta spoil yourself a little sometimes, you know?