Google "twitter profit". Still in business despite losing bigly for over a decade. At this point, I'm fairly confident that it is some kind of five-eyes public opinion monitor / propaganda vehicle, where other governments occasionally hitch a ride.

Before any major geopolitical happening (like the soleimani assassination), there is always a temporary ban-wave on a number of popular political accounts, left and right.

A "tankie" is actually a victim of a state-run psyop. Which state? Who knows?