There's a little efflorescence, but nothing out of the ordinary for the area; it's more uniform and nowhere near as severe as your picture. I suspect installing a barrier wouldn't make any sense. Because of how houses (and foundations) abut, largely limiting access to within the property's footprint, I imagine it would be easier to simply pour a new foundation. New foundations are increasingly common, but I'd rather not drop $30,000+ before I need to.

SF is coastal and foggy. Most of the western half of SF is built on sand dunes. Drainage is excellent but the ground is nonetheless perpetually wet. One of the things I've always noticed about typical first floor remodels is that they always feel very damp. They may be fancy and expensive but they always feel like jail cells to me. We recently toured a house around the corner from us with a 1990s- or 2000s-era first floor remodel and, indeed, you could both smell and see mold. Unless you pour a new, modern foundation (or somehow manage to install an external barrier) I don't think it can be avoided. It's crazy to me that people pay premiums for such remodeled houses. Like I said, I'm glad the house we found was relatively unmolested.

You're probably right that the reasonable thing to do is leave it alone and replace it when it gets too far along. But then I'd have no excuse to learn an old-school masonry skill. :)