Most who discuss better urban planning and focusing on less car-only design wouldn't consider having a SFH with land (now this depends) an issue even in a city or neighborhood adjacent to a city. A quarter acre of grass? Probably not except at great cost. A deep lot with a garage? Yea that's pretty practical. Ideally you'd have a mix of SFH, condos, apartments for rent, granny flats, and other housing options so you can accommodate people in different stages of their lives and at different price points.
Then of course as most would live in this mode, those who want large lots or lots of land would move further away.
> It's also carrying capacity, instead of making multiple inefficient trips to a local market multiple times a week I can get all my family's groceries in one trip once a week. Ditto for outdoor supplies, small furniture, Christmas Trees, etc
Is it really inefficient if it's a 10 minute walk away, or on your way home from your job? I think you'd really have to sit down on that and look at the whole context.
For oddball trips like a Christmas tree you have options including delivery, but what most people would suggest is that sure you still have a car for those trips (maybe one per family instead of two) but for most activities you don't have to drive. We get stuck on edge case scenarios so much that we over-optimize for them. It's like EVs. Many are like "but what if I go on a road trip", well how often do you go on a road trip? Once/year? Weekly? If it's once/year, well, figure it out.
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For example, most I'd argue are envisioning something more akin to German Village in Columbus: https://en.wikipedia.org/wiki/German_Village
Here you can see cars of course, but you can also see that many homes do in fact have deep lots which can be customized with grass, pavers, whatever you'd like. Of course not all homes have those (depends on socioeconomic capabilities) but you are also 5 minutes from a gigantic park with lots of green space.
In German Village you have cars, many homes have off-street parking, lots of pedestrian traffic, lots of bike traffic, tons of locally owned businesses and restaurants, and community events. I think people want more of this and wonder why we can't build like this anymore. Personally I think it's because developers, the government, and automakers are all heavily incentivized against it (not necessarily out of malice). Unsurprisingly, locations that are walkable like this have the highest property values despite often having crappy schools. If they had really good k-12 schools the property values would be immense.