In my view it only does so incrementally. At best you can double properties. Society would benefit more from joining lots to create a footprint for multi family dwellings, rather than dividing them.
It also seems like a bit of wishful thinking. When you ask most people, they want to live in a single family home. And that's what these guys are building. They're building to capitalize on the market, not to the overall benefit of society necessarily. But the latter makes great marketing so it gets woven into all the messaging, whether it's really maximizing social benefit as opposed to maximizing developer profit.
We aren't solving the affordable housing crisis in one fell swoop.
We are bending/slowing the insane growth in SFR prices and slowing/ending homeowner displacement.
As we scale we'll make a meaningful impact, but the solution to affordable housing is not just loosening artificial supply constraints, and is bigger than any one private (or public) organization.
I certainly admit to preferring a single family home myself, though it's never cost me more than about $1k/month for rent / mortgage / taxes. My current home is paid off.
But a lot of people are willing to make tradeoffs, e.g., the younger people passing through town, the elderly, and the poor, all have different housing preferences.