EveryDoor works great for this (marks 5+ yo POI’s with a yellow signing, not in the map but below), very useful when using your phone. On a computer, also Overpass Turbo is great, for example: https://overpass-turbo.eu/s/2vBx Click ‘run’ to see the results. Or you can modify the date and the location then run the script.

Don’t know if it’s a useful answer to your question, but might try offering the addition / updating of company locations info as a service to companies. For example check for a bunch of shop brands whether or not most of their shops are on osm, and if they aren’t (or very outdated), you make an offer to add/update. Then there are a few possible outcomes (besides no reaction):

• ‘yes, please help us!’
• ‘oh, we didn’t know OSM exists. Thanks for the tip, but we’ll manage it ourselves’ -> which is also a good outcome for OSM.
• ’why should we do that?’ / ‘no, too expensive’ -> evaluate your offer description or price

Don’t know if that will be afterward. There are also many useful YouTube videos available for explanations/training. Contributed to some HOTOSM projects in the past, but only recently started exploring the possibilities of JOSM myself, because many things (such as drawing in houses) can be done much faster and more efficiently. Online videos were a very useful starting point for this.