Yes, Reddit is going through its own API pains right now, and of course it is anyway a centralised social network much like Facebook and Twitter. So the discussion around alternatives has been coming up again. Lemmy has been around for a while, its technology is good, and it federates via ActivityPub to the rest...
Think of it like email. You are on one of the Lemmy providers, while we are on one of the Kbin providers, being able to send email to each other. :D