How would you solve it? I'll run by a few ideas from the perspective of the Netherlands, as I'm most familiar with it.
"Address land lords by more heavily taxing them or applying caps to rent".
Tried. Has the exact opposite effect. They'll just sell the property. There will be fewer rental homes with even more price pressure.
"Intervene in investing. Control what gets build, introduce price caps, who gets to buy it (for example teachers), etc"
Tried. Projects will simply be canceled. We have a 70% decline in new supply. In fairness, also due to the high interest rates.
"Land should be cheaper"
Can't be done over here. It's the main income for municipalities. Take this away and local taxes skyrocket.
"Building the home should be cheaper"
Can't be done. Materials are more expensive, so is labor, and building standards are much more complicated.
All of the above applies regardless of zoning. So you're in the situation where building a new home costs about 400K at least. Your idea of an affordable home is 200K.
Do share how you plan to solve that?
It's obvious that there's no easy fix, otherwise somebody in the many countries that have this problem would have fixed it already.