My sister can't move her feet at the ankle. She'll never drive unless we can afford a custom 50k car. She has a 3,000 dollar mobility scooter. We had to spend about a month mapping the city to figure out WHERE THE FUCK SHE COULD GET ON AND OFF THE SIDEWALK.
Edit: Let me elaborate further:
It was so bad, that if we didn't think ahead, we would have to go back a half a mile. I'm not joking. You ever seen those roads between neighborhoods with no turn offs? Better make sure that side walk ends with a ramp, otherwise, you have to go ALL the way back. You also can't lift the scooter, it's over 100lb. If you're reading this, please petition your town to add more ramps to the sidewalk.
My sister has to have every bone from her pelvis to her ankle broken, REGULARLY. They have to cut all of her muscles, stretch them, reconnect them, and then inject them with botox. They then set them in a cast. This is just so she can properly grow, due to cerebral paulsy. And then, just to rub dirt in the wound, we can't even use the sidewalk properly. We're surrounded by beautiful nature and trails. She doesn't get to experience that. Please petition your towns to add more ramps to the sidewalk. I'll get off my soap box.
Just make it national law to follow an industry standard that includes ramps everywhere a intentional transition between roads or entrances to properties are.
Germany has DIN 18317 and DIN 18318 for that.
DIN = Deutsche Industrie Norm (German industry standard)
Sidewalks with ramps on them are a technology that has existed for a very long time. The only reason they aren't there, is because somebody didn't want to pay for them. I'm not blaming cars. I'm blaming politicians that are lazy as fuck about actually helping their people. And to an extent, many of those people, for not recognizing this as an obvious issue and pushing for it to be fixed.
It never ceases to amaze me, as a child and care giver of a parent with physical disabilities, how much this world is designed with no regard for people. It's incredible. Fuck city planners.
My mom had a similar issue in our town, though no where near as bad. Her wheelchair is quite a bit heavier, but we got a small folding ramp that we bungee to the back of her chair and take with us everywhere. Whenever we find somewhere that she can't go because of a step of less than 12 inches/30cm we can use that. It it's more than that, we just have to figure something else out or not go there. It's not okay the way everything is designed. And it doesn't make sense. Everyone, regardless of mobility, can use a ramp, not everyone can use a step. Why is it so hard to get the fucking ramp?
I am a healthy adult and I'm also continually enraged at the state of sidewalks in my area. When I walk my dog there are some routes I simply cannot take because the sidewalk just... ends. I think some lots extend all of the way to the street and it's up to the property owner to put in sidewalks and many simply don't. If I walk across their lawn to get to the next private sidewalk I get yelled at for messing up the grass that they spend "so much time and money" maintaining; fine, it's your property and I'll stay off, but what a waste of resources. Unless it's a particularly quiet road, I shouldn't have to walk in the street. The city-maintained sidewalks that do exist are a travesty: no curb cuts as you noted, tree roots that create huge steps, holes, and some have no curbs so people just drive on the sidewalk. The city doesn't want to do anything about it because these are either privately "maintained" and they can't, or it costs money and they don't want to.
I do think that mobility scooters should come in off-road versions because I've never seen one. I don't see why $3000 can't buy something closer to an electric ATV with knobbly tires, full suspension, and a torquey motor that can mount curbs like a boss, but it's a chair format and is limited to fast-walking speeds so that it isn't a car. It's probably a low-volume issue.