Pixelfed/Mastodon/etc sort of work with Lemmy, in that they can see Lemmy posts. Lemmy can see posts from them if you tag them appropriately, which rarely happens. They only sort of federate properly. And yeah, Loops is like TikTok for the Fediverse.

I’m not saying PieFed is better than Lemmy, just saying that apart from Lemmy, your best option is probably PieFed atm.