Land might be finite but we're nowhere near its limits. I once read that you could easily fit every human building ever built in a 10km stretch of the Grand Canyon. So let's carefully say we can have 1e9 times the number of buildings we have now.
That’s especially true of land where, as the other commenter says, all land is decidedly not created equal. There are very good reasons more people want to live in Manhattan than in Death Valley.