At least here in California the big driver is Prop 13. The flat parking lots all over Los Angeles have been owned by the same people for decades, usually since the 70s or earlier, so they’re paying a few thousand bucks in property tax while absolute raking in cash - they can usually meet their obligations with a week of revenue and the constant cash flow is a guaranteed lever for credit and loans. Selling or redeveloping the lots would trigger a reassessment, so the owners just keep them as the cash cow they are.

I have a friend who inherited three such lots in downtown ($$$) and he lives very comfortably off just that revenue because their old assessments totaled under a million so they never got reassessed (though the rules have become far less generous with Prop 19).