> They are speculating that the value will not decrease, or that rents will increase. Otherwise they’d rent.
That assumes you're getting the same product, but when renting you don't necessarily have any guarantee that the lease will be renewed when your rental term is up. Owning your own home is a more stable arrangement since you generally face no risk of eviction as long as you keep up with any applicable mortgage and property tax payments (barring exceptional circumstances such as eminent domain).
If you expect to move frequently then it might come down to just rent vs. mortgage and property value, but if you intend to stay in one place for the long term then ownership has other advantages to offer.