Without being reductive, though: there's obviously a middle-ground here. For example, property/space is "owned" by entities in Second Life and those owners can kick/ban others who aren't behaving from their space. It seems entirely possible for a large, 3D space to have areas where brands (or other entities) can ensure they have a penis-free space without dictating what the rest of the "world" is like.
It's not just certain websites anymore. The internet is no longer decentralized like it used to be. Independent communities are pretty much dead. Now everything is on Facebook, Instagram, Twitter, Reddit, whatever. All of these are advertising companies and they regulate what you can and can't say there. Basically you can't say or do anything that offends these advertisers.
I'd rather have a free internet where I can witness the full spectrum of humanity, good and bad. Not what some company or even some government deems acceptable.
As always, advertising is the root of all the evils we face today in our technological society. When is this industry gonna be regulated out of existence?