No need to create their own platform, they can use phpBB!

I don’t see why not since progressive leftist describes where their beliefs lie and authoritarianism describes how they go about enforcing their beliefs.

Really depends on how specific you want to be with the definition of leftist though.

You want dancing baby? This is how you get dancing baby.

It usually boils down to this, something can be strictly better but not perfect.

The ability to audit the code is usually strictly better than closed source. Though I’m sure an argument could be made about exposing the code base to bad actors I generally think it’s a worthy trade off.