I added this concerns to list in the first post
For vs ground truth - is it actually something that happens? In my experience this chains list accurate info on their websites.
Though tiny shops often have outdated info
For divergence of effort - it is balanced that effort that would be anyway going into ATP is useful also for OSM.
There’s a postal service here of which the local branch has different opening hours than the ones mentioned in the main website of the chain. And that one is correct in this case, as you read it on the door, and not the one on the website.
It may be a rare occurrence, but because it exists, I would like to assume that indeed it may actually happen.
This aspect can be adressed by checking the source listed by the person who added the original hours (if it includes Survey or Local Knowledge) or more strictly, simply combing through conflicting opening hours manually.