According to Israeli law, the government owns nearly all of the land, except for some privately owned land from Mandatory periods. Citizens get to rent it from the government. This is commonly known as "buying land", even though technically it's only being rented.
That is the view of Israeli law. But what about halacha?
According to halacha, can it be that the entire population doesn't own their land?
I think that the fact that people refer to it as "buying" land, not "leasing", might have an impact on the way halacha views the contract.
Some side effects of not owning are that (most likely) anyone leasing land would be subcontracting, which i think (though by no means am i sure) is forbidden. Also, bikkurim can only be brought from land that you own.