Agenda 21 is a code name for a master plan, originated at the United Nations to change...

... the political & economic system of the world to one of total collectivism. in order to do that people must not be allowed to have independence, they must be dependent on the state / government for everything otherwise they won’t be easily controlled.

That means they can’t have private property, mostly they cannot have land of their own, they have to live in preferably high rise flats or apartments that are provided to them by the state as a benefit.

These people at the top want all humans to be dependent on the large S of the state, they don’t want anybody living out in the boonies.