You might be surprised at what I've seen :-).

The situation you describe :

New buildings are being built dime and dozen because rents are there to support them. People are no longer buying home to live, they're buying homes so that they can rent it out, because rent prices are high. A whole slew of new buildings are being built because they can rely on exorbitantly high rents.

Describes what most economists think of as inflation, not a social justice issue per se. Typically the limiter on this will be the supply of capital, and with zero percent interest rates there is very little limit. The way that works is someone borrows money X at 0.5% annual interest to buy a house which provides 3 - 5% of X annually. They borrowed at .5% and their return is 3 - 5% giving them 2.5 - 4.5% of "yield" for large sums people will do that for only 1 or 2 % yield. That is how markets allocate capital.

The housing market has limits on how fast or far it can grow. I'm very familiar with both the SF Bay Area markets which were over constrained, and the Las Vegas NV area markets which were largely unconstrained. Mortgage crisis aside, houses in the Bay area tend to increase because of contraints on new construction, and houses in Las Vegas tended to decrease because there were always new houses coming on the market so you had to "discount" the value of the house to get a buyer who would otherwise buy a new house.

In housing markets there is a tension between rent prices and mortgage prices. The cost of a mortgage results in a monthly payment X and rent costs Y. When Y > X people start buying places rather than rent them because not only is the cost lower per month, but when they transact out of the house or condo they often get some additional "equity" that has built up as a function of them paying down the mortgage and/or appreciation of the asset.

This however is unsupported : Real Estate is one of the fundamental reasons behind creating the modern urban poor and homeless.

Modern urban poor and homeless are a function of wage disparity.

Understand that a place has a relatively fixed amount [1] of housing, it also has a available various jobs near by. Those jobs pay a wage and a fraction of that wage is available to the landlords in the area as rent. It is impossible to raise the rents above the available wage fraction, people simply won't rent your space. This is why a house in Holland Michigan can only sell for $109,000 when the exact same house in San Francisco can sell for $1.5M. In Holland you are doing great if your job pays $60,000 a year, in San Francisco there are jobs that pay $200,000 a year.

So you take the amount of money being paid out to workers, and take the fraction of that people are willing to spend on housing. And you get the total available rent/mortgage dollars in a region[2]. That pool is fixed, but it isn't evenly distributed. So tech workers will bring home big pay checks and wait staff much smaller pay checks. And when the number of available spots runs out (priced out by the market dynamics like "close to work" or "good view") they are gone, and pressure is applied to create new spaces or try to capture more of that value by raising rents.

> As somebody deeply affected by the ever-increasing
> rent prices, I believe Germany is doing the
> practically right thing.

Can you share why you haven't switched over to owning from renting ? I am guessing that you must have looked into it, what are mortgage rates and median house prices where you live? No need to be specific about your location just sort of the market parameters that are keeping rents going up.

[1] It changes due to new building and old buildings being destroyed but much less quickly than the job opportunities change.

[2] We'll leave out places like New York or London where billionaires buy apartments but don't live there.