Your overall point is certainly valid, but there's no "dichotomy" there. I'd say "sidewalks are for people, not X" where X is pretty much anything that's not people (including scooters and bikes, even though there are people on them).
If those delivery drivers were parked on the sidewalk, it would be a different discussion. Or if the robots were in the bike lane, we'd be saying "bike lanes are for bikes, not robots".
My point is that you aren't simply pushing robots off the sidewalk and getting a better city. You have externalized the problem somewhere else. "Look, our streets are free of garbage", he says, dumping it all into the ocean...
It’s not clear to me there even is a “problem”. We did just fine before there were either robots or DoorDash drivers clogging up the road/sidewalk. (Admittedly DoorDash was very handy in 2020.) The problem is in allowing commercial interests to unilaterally clog public infrastructure.
But isn't this whole concept externalizing the commercial micro-transit problem onto pedestrian-only right of way? The sidewalk is the ocean in this metaphor.
If those delivery drivers were parked on the sidewalk, it would be a different discussion. Or if the robots were in the bike lane, we'd be saying "bike lanes are for bikes, not robots".