The investors aren't building the houses. They're not developers. They're speculators. They're the real estate equivalent of scalpers buying up all the Taylor Swift tickets and reselling at huge markups. Except they're doing it with shelter, a basic human need, rather than a luxury entertainment product.
Houses aren't being built. We've had a huge reduction in construction essentially since 2008. This is why the scalper analogy fits: it's a largely fixed supply with skyrocketing demand and investors see it as a gold rush.
The problem with houses is if you just build - it won't solve anything. They have to be built in desirable locations. But then you've to either replace existing buildings in there. Or you need to extend commuting infrastructure. And in either case you need to build/upgrade social infrastructure. Including workforce for it.
Prices of housing or tswift tickets aren't going up because investors/scalpers, they are going up because again there's excess demand versus supply.
Your entire example is predicated on this very fact: scalpers cannot compel middle age white women to all the sudden want to attend a concert, same way investors cannot induce genz kids to want to move to vancouver.
Make more houses or taylor swift tickets and the whole thing resolves itself.
