It works, but it's no good for daily driving. You can get out of town in a car with some patience, but you're going to take the train in town.
If you can accept that, you can have it all. But no American city has made that choice.
At least part of the issue is a chicken and egg type problem. Older city housing stock mostly does not meet your criteria (or it does but costs several millions of dollars and has no density), so people oppose dense urban housing, so it doesn't get built, so we never get to see how it actually can meet the criteria people care about.
Not everywhere. Salt Lake City for example has wide streets and multi-story underground garages to allow locals and commuters alike to drive to the city, with a walkable city center above the garages. The newest residential buildings in the city also advertise their double-walled soundproofing between units.
One issue I have with a lot of smaller cities with walkable cores is that you run out of choices pretty quickly. I'm familiar with a number of places in that vein and they're fine to visit once in a while but I think I'd tire of them as an example of "city living" pretty quickly if I were looking for that sort of thing.
- SF is going to be a lot more crowded, noisy, less clean, obvious signs of poverty. Nothing you can really do to address it other than be aware that some areas are best generally avoided.
- On the other hand, SF has a lot more culture, restaurant variety, and is just a more interesting urban environment than SLC. So, basically, take advantage of that. SF, more than even most larger cities, has a huge number of interesting nooks and crannies to explore.
- Generally speaking, smaller cities often do have some degree of walkability in a central core but you're still crowded in to some degree while you lack the variety and opportunities that preferred large cities have to offer. (I'm not personally much of a fan of smaller cities. I think they tend to have city disadvantages without giving me offsetting benefits.)
Markets would probably also provide units without all the above and while you may not want to live there, perhaps someone would accept it rather than not be able to live in an area at all.
Make it so I can still store my car (near) my unit. Also that there's a GOOD loading dock so I can get items to/from my unit and transport.
This might be a mega-garage at the edge of a city with moving belt people movers and giant commercial promenades that are covered indoor malls /between/ buildings.
It might just be more parking under the building out of sight.
I also NEED sufficient privacy. I don't want to hear my neighbors slamming the microwave around, food processioning, or cleaning. Nor do I want to hear that idiot above me who thuds around too much. Build it in to the fire and privacy codes that there WILL be walls of sufficient thickness.
Make that inner wall a complete full one, no plumbing or electrical/etc. That's where all of the insulation goes. That's the disconnect between units. Then /outside/ of that build the utility / facing wall that isn't for support, it's for finishing and routing of wall items.
The roof? I'm not sure how to handle that other than, maybe something similar.
Then, what I want, give me a good choice of true high-speed (Ethernet/Fiber) ISPs.
Also, what other people want. Do all of the above, but also build in PLENTY of FAMILY sized units. Units with 4+ real rooms and a common area. Also make it easier to sublet within those rooms for friends (this means the inner doors might need locks as well, and should also sound-isolate).