Lemmy doesn’t have a collective culture. Each instance has it’s own culture or will develop it over time, even though a lot of reddit vestige remains. (It’s only been like 2 months)
I don’t think toxicity ever will get too bad here, for the simple fact that if you don’t like the say, c/politics of one instance, you are always free to go to the c/politics of another instance or even start your own.
Eventually, the toxic instances/community will bleed users and die out, defed is a factor but doesn’t have too much to do with this.
DraftEdge for a direct AutoCAD replacement, Revit if you are really serious.