I think one can be extremely wealthy without owning a square metre of land. Land is of course very valuable in, say, cities such as New York or Tokyo. However land is only of value if one can derive an income from it.
The extreme naivety exhibited is amusing. It needs to be understood that all kinds of income like salary or profits or revenue comes from an initial investment in land and its usage.
It is the fallacy of the young world to be oblivious of the fact that almost all real capital existing in this world is out of land, and its notional and relative valuation.
Furthermore, a desert in the sahara has a value to the owners even if you do not derive an income out of it.