this sounds nice, but neglects the fact that (1) materials cost has gone up and (2) zoning requirements exist. (1) means its just more expensive to build overall, and (2) means that a lot of proposals for apartment complexes get voted down.
Part of building more is getting government (mostly) out of it so that things like zoning laws don't hamper new development. Obviously that is very hard to do at a local level when incumbent homeowners' housing values would be cut in half overnight.
This is happening in california. In fact there are three current situations:
1/SB9 cutting R1 lots in half
2/ ADU laws, which let you build up to 3 homes/units where there was one and further, can be combined with SB 9
3/ AB2011 which lets you turn defunct strip malls into housing
Honestly, this plus things like PermitFlow make me feel like we will be able to build enough. The issue will be making sure the housing is affordable rather than expensive and empty.
You're not wrong. There are multiple aspects of government involvement that require untangling which includes federally backed mortgages that allow banks to be more lax on loan terms (which is how we got 30 year loans and Trump proposing a 50 year)
Actual NIMBY/YIMBY fights look like one level of government representing a lot of people who can't afford a primary residence fighting against a different level of government representing a lot of incumbent primary residence owners who are concerned on a personal level about the negative externalities of more people being able to live in their neighborhood. Government is happening no matter what.