There's no government restrictions preventing you from assembling elsewhere.

Your interpretation would make shutting down any place where people assembled unconstitutional which was clearly never the intent.

Of course you can. Nothing stops the same group of people from congregating on Discord, Rumble, or even in real life.

If you used to assemble at a public park, and the city closes the park entirely to turn it into something else, does that violate your right to assemble too?