What incentive do we, as a society, have for foreigners to use our land as a piggy bank?

Given we already have chronic undersupply, shouldn't the default position be to prioritize citizens and others who can demonstrate a greater need?

Assuming we could build more, in theory economies of scale would result from more development happening regardless of who the buyer is. And it would in theory result in overbuilding capacity for that many residents and then being left with spare capacity, the cost of which would be allocated in equal part ideally to the investor properties as well.