Private ownership of land does take it away from the community. The problem is that we've gotten so used to everything being privately owned, that we've grown blind to the possibility of land not being owned by anyone and belonging to everybody.

Land that isn't private is still owned by the government, and maintained by taxes. I wouldn't say public land is belongs to everyone, so much as it belongs to no one - there are limits to what it can be used for e.g. can I build a house on such land?

this thread is about UBI, which is currently impossible without new laws, so why not look at what could be possible with new laws regarding land?

Go ahead.

The community lost the land when it was doled out to the first private landowner, which may have occurred centuries ago.

Or when the first settler settled there and defended it, before which there may have been no persistent local community.

Are we not talking about modern society though?