Renting itself isn't inherently the problem if you have very strong tenant rights. Imagine renting came with all the rights of owning except the money flowed differently (like a perpetual mortgage) - that'd be pretty okay, actually. It is within the power of a government to enable something like that.

But renting is a problem if there's no asset at the end of it.

Even if rents were capped at half what a mortgage for the same property is, you still are in a position that once the asset of the house is paid off the landlord now has an asset that earns income without labour.

And the inverse.

Regardless of what you earn (to a point, even into higher income brackets), if you do not put it into an asset that can house you, and you stop earning, you cannot live without reducing your overall capital.

So rental means a lack of opportunity to reduce your labour dependent income over time (important as you age), and a reduced ability to weather negative life events.