I get pretty frustrated when someone walks slower than me and keeps lurching back and forth so I can't overtake. Idk why, might miss bus maybe.
I don't say or do anything, though sometimes I nip onto the road or between some tight terrain to overtake
I don't think that's ableist, even if they're on crutches or whatever. You're trying to go somewhere and being impeded. What would be ableist is treating them poorly for this instead of remembering that they probably wish that they could go faster too.