It isn’t a matter of virtual vs. physical. It’s a matter of ownership.
The public town center, real or virtual, is owned by the public. The speakers are the owners.
The social media companies are owned by their shareholders who get to decide what speech is allowed.
When the government owns a social media platform censorship on that platform will be illegal.
This is the very point though - it shouldn’t matter if you’re a private company, if you create a public space it is a public space - free speech applies regardless if it is physical or virtual. Twitter is even described as “the new public square”.
I’m suggesting we evolve our notion of “public space” and bring it into the 21st century by including virtual spaces that are free and public. If you want it private then charge for entry and impose as many rules as you like - just like private clubs.