Stair reform makes it possible to build units that "live like a house" not just because they are LARGE but also because they have a QUIET side.
Houses have a front and a back. A front facing the public street, and a back that opens onto a private yard.
Multifamily CAN do that if it includes units that have a front and a back, or "dual aspect." And these can be really nice if primary bedrooms and kitchens are facing courtyard, or quiet side of the house, so you can open a window at night, or have a dinner on a balcony or whatever.
Not all the units need to be front to back. Pack some floors with studios and one bedrooms for MOAR units (and people to share expensive land with, patronize shops, eventually buy large units when those households are ready to downsize, etc.)
But some floors should have large units that are house-like in that they have a street side and a quiet backyard side.
No urban revival without stair reform.
Great cities need middle housing -- ie MANY small multifamily buildings that allow many households to share expensive urban land. But those homes still have to be good enough that a wide range of households want to live in the. Not just twenty somethings.
Current egress rules have made multifamily housing ESPECIALLY awful in the US because they push developers to double-loaded corridor layouts: long, hotel-like hallways with apartments lined up on both sides. These buildings are extremely expensive to build and not great at creating "life-cycle" housing.
Families often want a home with a “front” and a “back”: one side connected to the street and the life of the neighborhood, and another quieter side facing a courtyard, garden, yard, or shared green space. They want cross-ventilation, daylight from more than one direction, a place for children to play, and some sense of threshold between public and private life. Double-loaded corridor buildings make that impossible, because units are facing either the back or the front.
The more home-like form of multifamily is enabled by single-stair reform, sometimes called “smart stair” reform and closely related to the point-access block. instead of accessing units from a long corridor, apartments are arranged around a central stair. This allows smaller buildings, shallower floorplates, more dual-aspect units (they don't all need to be, but some of them should be), better light and air, and a much closer relationship between the home, the street, and the yard.
Single-stair reform is a keystone reform for rebuilding family-friendly urban neighborhoods. It will make it significantly easier to build the fine-grained, middle housing neighborhoods that everyone wants but no one builds anymore (because we made it illegal)