While vehicles partially on the sidewalk are a nuisance, they do provide a barrier between pedestrians and vehicles, and do have a traffic calming effect by narrowing the travel lane.
And they're excellent barriers for preventing people in wheelchairs or using walkers to get through at all.
That's why you have road markings (e.g. double / broken-single yellow line) to prohibit parking in front of curb cuts. Since curb cuts are frequently-spaced, it's not too hard to find a gap.
In my experience people don't care about those markings at all. They'll park anywhere the car can physically fit into that won't unreasonably block other car traffic (and sometimes even then ...).
Vehicles partially on a sidewalk probably shouldn't be surprised if they are found with broken headlights, taillights and scratched paint.
In the places where this practice is common, it is also accepted.
Not true in Taiwan, nearly every sidewalk is overflowing with cars and scooters illegally parked. I started closing mirrors and opening windshield wipers on cars that do this to try to get the zeitgeist moving and someone threatened to kill me for it recently.
“Accepted” is a generality. There are individuals with beliefs counter to the norm in every city.