I've moved to a smaller city; and while things are clean and generally well maintained, there are many neglected sections of sidewalks here which would not be accessible to some forms of wheelchair. I do a lot of walking so I am in a good position to gather data like this, but it seems that the effort for this is not as organized.
There are also some non-wheelchair accessibility issues in mapping between new construction and old; for example, textured pavement placed according to new standards, further back from the roadway, but the zebra crossing marks and stop lines were painted according to older standards, closer to the roadway.
I think it would be nice not only to treat this as a repository of useful information for people looking to access these ways, but as a tool to identify, triage, and resolve accessibility issues.