The developers of Lemmy also run lemmygrad.ml and lemmy.ml, the former being a hardcore communist anti-everything delusional conspiracy crapshoot of a platform, the latter a tiny bit more relaxed, but moderated/administered by a bunch of dicks that are essentially also tankies (= hardcore leftists) and Russia fans/apologists.

They (the devs) recently asked for funding to support their work, and in doing so, disclosed that part of the funding would be used to run those two instances, thus giving users no alternative to support without cross-financing extremism.

Piefed is developed independently and has none of those links to moronic ideologies.

Piefed as a platform uses the same underlying protocol as lemmy, mastodon, etc. (Activity Hub), so users can seamlessly interact with one another.