Builders these days don't build reasonably sized homes unfortunately. I wonder if cities don't want them because it'll attract lower income folks.

The economies of scale of setting up a job site, lining up all the contractors' schedules, getting all the materials and equipment in place, plus the paperwork of permitting, inspections, etc., mean that each additional square foot/meter of space is much, much cheaper than the first. That just naturally pushes towards bigger single family homes.

Multifamily is different, though, which is why many multifamily buildings gravitate towards 1- or 2-bedroom units.