That tightness spills into the rental market directly. When months of supply on the ownership side stays this low, buyers who cannot find or afford a home to purchase stay renters for longer than they planned, which adds demand to a rental pool that was not built to absorb it.
Purpose-built rental construction has not kept pace with either source of demand, so the units that do exist see more competition per listing than they did a few years ago. That is a supply and demand story, not a single policy or landlord decision.
For an owner watching this from the other side, a tight rental market is often the signal that it is a strong time to sell rather than hold. Get your hand-reviewed valuation from Joel Dyck.