I just catalogue tankies as another flavor of right-wing. Any kind of authoritarianism is far-right as far as I'm concerned, whether it's supposedly in service of communism or anything else.

Being left is about finding actual working solutions that help people and make society more free, just and safe for everyone and it's about being willing to abandon solutions that have been tried and don't work towards that goal (or require massive amounts of blood to achieve).

A tankie insisting that you need to just purge the political undesirables to make a utopia is just as irrational and right-wing as MAGA chud thinking theocracy or an ethnostate will work.

"Centrists" in the US think you're meant to cut the difference between those two, which is why they end up conservative themselves. They're stuck in a conception of the political landscape that limits them to thinking of things as a spectrum of extremes, rather than a binary between stuff that works to produce material good and stuff that doesnt.