To add to this: tankies are leftist MAGA. It's not what they (claim to) believe so much as they are toxic trolls who deny facts and reality itself. Discussions with them tend to be very unpleasant, since they use "alternative facts" and incel-style reasoning - e.g. when you block them they are quite proud of how they simply make a new account and keep right on going. No does not mean no to them but rather to simply push harder.

https://en.wikipedia.org/wiki/Tankie You'll start noticing those opinions mainly from specific instances. If it's not your thing, don't hesitate to block communities, users, or whole instances before giving up. You can use Lemmy the way you like.

on lemmy, its usually a far left take on politics. when it comes to specific things like russia, china, N korea, cuba,,,etc. tankies on reddit can mean politics, or specific things like a city/location based sub (how you need to act a certain way or believe a certain way).