Gate and ground agents are generally very mobile -- at least I'm pretty sure UA doesn't chain them to the gates -- though there may be labor/contractual considerations (see below for IAD example) but I don't know what SFO is doing well enough to have an opinion.

Aside from COVID-specific concerns, there may be "leveling" concerns also in play -- if you assume that all of the attributes of a gate have some finite lifespan (big things like jetways and smaller things like carpet, seating/gate furniture) there may be arguments depending on how its accounted for and who's responsible for maintenance to use each of the assets a little bit rather than concentrating all of that use on a limited number of gates thus accelerating the requirements for heavy maintenance/replacement/overhaul while leaving other assets under utilized.

There may also be contractual gate utilization requirements, particularly as it relates to "use it or lose it" for gates or concession leases/guarantees (something like concessionaires not being obligated to pay full rent if fewer than X flights/day/week/month use adjoining gates)

I've only had a couple flights through ORD but I've spent way more time than I'd like at IAD and -- at least when I'm there they definitely aren't consolidated. I've connected D30 to A1B (and similar absurdities) while hoofing past loads of unused (no upcoming flight on board/no aircraft at gate) gates. My perception could be wrong but I feel like I'm doing more hoofing at IAD now than pre-COVID. IAD also, though, has some harder constraints, e.g. IIRC, at IAD all of the below-the-wing handling on A is done under contract by Swissport, and I think that's also true for the upper D gates, but not positive what's going on with Low D, and C IIRC is all UA BTW.