> I also struggle to remember ever seeing an SFPD officer patrolling this neighborhood (two blocks from a major police station) on foot.

Footbeats have been cut back from pretty much all police incl. in Europe.

Policing(even moreso with reduced personnel) is more reactive than preventative. Getting from A to B and dealing with issue in B is generally quicker and safer by vehicle than having somebody run to B and then dealing with issue. Limited energy stores etc.