Canada

Two things would work:
-Fix the fucking restrictive residential zoning regs. This is provincial turf.
-Build more public housing. This is also provincial turf, but the feds had been involved in the past.

Everything else is window-dressing.

With enough supply, appreciation stops, or maybe declines if construction overshoot demands. Rental companies then have to make their money off of rent alone, but the margins are usually pretty thin, and with a sufficient supply, units start going empty if the rents are higher than what the market will bear. Companies will only hold on to units for so long before flipping, just to cut tax, loan interest and utility costs. A flat market is also a good deterrent for speculators, especially in a higher interest rate era. They can make more money elsewhere.

Having said that, I've moved a lot for work. I've had good job offers in Calgary, Vancouver and Toronto. The negative impact on my quality of life just wasn't worth it. I did live in Regina for 10 years and am now in Winnipeg. Housing never really got out of control in either place, commutes are either a 20 minute bus ride or walk/bicycle. Door to door currently is a 25 minute walk to the office, and I can do a big chunk of that in the Skywalk.