[sidfthec]

> I can take it home with me.

I own part of Google. I can't take it home with me. I don't even know what that would mean.

> If I own it, I can get a permit to build on it.

It is indeed possible to get a permit to build on/use public grounds.

> If I own it, I can refuse to allow everyone else to use it.

You can vote for representation that could in theory restrict access to just you. The other owners probably wouldn't agree to it, though. There are a lot of owners who want open access.

I think you're confusing things here. You seem to be talking about having full ownership of something, as if partial ownership isn't a thing.