Not just land, but regulations and building codes are so strict that the base cost of new high density housing is so high that it isn’t economical to offer as lower rent or lower cost than “luxury” without some form of subsidy. So these things need to be built and sold or rented to the relatively wealthy so that 30 years from now they are depreciated enough that they can be offered to lower income groups.

Honestly, they are in fact Luxury apartments. Absolutely gorgeous and well appointed with huge swimming pools and excellent gyms. Maintained to impeccable standards. Beautiful kitchens with excellent appliances. The whole nine yards.

https://www.lyonliving.com/santa-ana-california/the-marke

https://www.rentmadisonnewport.com

https://estelleliving.com/gallery/

Most of those amenities other than the pool don't add very much to the cost of construction at all, especially interior finishes. When the cost of land is so high and the number of units you can build is artificially capped you have to charge a certain level of rent to hit the 3-5% margin required to get loans for a project. At a high enough rent, your renters will demand some amenities that competing projects will build.

All of the buildings you're linking to are mid-rise developments with VERY low lot coverage dictated by local zoning. The look nice, but not that amazing compared to other new development around the country.

My point being, you can't just build cheap housing on astronomically expensive land, the math doesn't work. Crazy zoning laws add to that cost. Pointing to new development as the problem is simply wrong. If people want new construction at a lower level of affordability, then they need to change laws that drive up the costs of building. If the banks won't/can't loan money to a real estate project with an expected margin of return of < 3%, then what do you expect?