It depends on who you ask!
For me, things like opening hours or paid parking indications are very helpful.
My girlfriend was doing some running training a while ago and in summer during the day it can be quite hot. But at night, how do you know which roads are lit if you want to plan your route ahead of time to have the right distance? Easy: OSM has the data, OsmAnd and others can display it... except our area had almost no coverage at all. StreetComplete made it super easy for me to map that, so now it's there. She stopped running in the meantime but... hopefully the next person can make use of it, the data is there to stay :)
For the wheelchair questions, there is of course another audience that might like to plan routes without finding inaccessible steps in the middle.
I can also imagine if you drive trucks, having good weight/width/height limit data is also useful. Right now I think this data is quite incomplete (though I didn't do a comprehensive study) and I have no idea what those companies use instead (maybe they just drive a route before sending trucks down it?), but at some point a free worldwide uniform dataset is going to be easier than whatever they use now.