US cities have trees, too. One downside, though, is the roots can grow and break up the sidewalk. There are some sidewalks in Seattle that are completely inaccessible to wheelchairs or even folks with walkers.
If roots were the biggest obstacle for wheelchair use, I'm sure many a wheelchair user would rejoice. I doubt that's anywhere near the case. Cars parking on the pavement, silly delivery robots, shops with oversized signs, all kinds of rubbish, inaccessibly high kerbs, are likely bigger issues.