Whenever this comes up I find people are incapable of grasping the scale of the issue.

Owning a second home isn't unethical. I think a rental market in an economy is healthy. This can be provided by individuals or companies.

The issue is supply and demand. The houses cost that much because people will pay it. Why? Well there isn't enough for everyone. If renting was banned housing numbers would drop. It would short term help some people buy a house but more people would be out on their arse than magically in a house they own. The issue is then increased in the next generation. Banning renting is not the answer.

Why is there a supply and demand issue? Because people with wealth want to keep it that way. If someone lives in a house and intends to say in it until they die it doesn't matter if their house is would 0 or value of an entire country. People buying and selling for a profit in the future is the issue not renting. That profit is only their with supply and demand issues getting worse so no new houses can be built. This means zoning laws, no higher density when a city gets 100x more people and no building on greenery meaning the city can't go up or out (going up is much, much better). No new cities are built. Then for demand issues population must go up at all costs, so immigration is a must. These same people have businesses usually so this is good because it can also keep wages down by getting people in from the third world and keeping house prices high and wages low.

Then there is the issue of debt and intergenerational transfer of wealth from the young to the old. Which really fucks with an economy and society at large when you think about it.

The solutions are this. The world and countries are finite, population would ideally go down. There is demand for high density buildings. Build it, knock down entire areas and rebuild. Build a new city, build more public transport to nearby towns that can be commutable. Just build! The young start off in debt and give money to corporations or the older generations that have no debt and everything they need for life. The youth need things so give it to them. Even low government loans or even better money. You need 20% deposit get a cash transfer from the government at say 25 worth 20% of an average house national wide. That will sort out the problem.

There is so so much money held up in mortgages and rent that if houses prices collapsed a lot more people would have a lot more discretionary income to spend and that would grow the economy.