For lunch, I'm fine with a handful of options. Heck, I was good with the handful of decent lunchtime restaurants in downtown Nashua NH for a number of years. But for the tradeoffs involved with actually living in a city, I want a lot more than a reliable rotation of restaurants.
Specifically with respect to SF vs. SLC though it's somewhat general to coastal big city vs. relatively prosperous smaller city:
- 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.)