I think a big part of the supply problem and the generational difference in ownership is the size creep of homes. Homes have been getting bigger and bigger to support the same sized families meanwhile wages have stagnated. Thats all extra flooring, walls, insulation, labor to build, energy to heat, wires to run, property taxes to pay etc. We need to change the way the supply is skewed and start offering more reasonably sized homes.
Sure if you want and can afford a 2500+ sqft 3 storey house then shop for that, we build lots of those, but we don't build lots of 500-1200 sqft homes which reflect the size of starter homes from decades ago. Many homes this size need to be custom built or are built by smaller developers. We don't see entire neighborhoods of these sized homes anymore. Same goes for apartments, they've experienced luxury condo creep despite demand for that level of luxury being met already.