I only use Reddit for two things these days. Practicing my technical writing skills by offering answers to ELI5 posts, and silently doomscrolling though US politics.
Both of these are theoretically on Lemmy somewhere, but this place really doesn't move fast enough to be fulfilling.
That said, I only access Reddit on desktop PC in old.reddit mode. The third party appocalypse did not make me leave completely, but it did kill off all of my time using it on mobile, at least. The day they take old.reddit from me and force me to use that miserable card view, though, I'm checking out for good.
When that inevitable day arrives, I will not have FOMO over it. Anything positive I'd hypothetically be missing out on would be canceled out by the abysmal way in which they expect me to consume it. I will miss what it was, though. Lemmy just isn't a substitute for it. The Lemmy experience right now is the Miracle Whip to Reddit's mayo.