Used that in the past and got a notification when suggestion was accepted & pushed to the map.
I’d guess it’s curated somehow.
But there is definitely some edit crowd sourcing, it may just suffer from a smaller or less motivated user base. Speaking of the latter, I've never seen Apple really try to incentivize it either, whereas at least at one point Google had a fairly fleshed out actual gamification for Google Maps where people could sign up to be "Local Guides", earn points for constructive actions, and get badges that could be publicly displayed. Essentially free for Google (dunno if they ever gave anything else to top editors for PR, but they didn't promise it) but even simple public recognition of an icon can be surprisingly motivating for a lot of people. I don't know how active that still is and also vaguely remember stories about editing tools getting shut down a few years back, but at any rate Apple has never really tried anything like that at all AFAIK. Not that as a corporate culture they've ever really gotten gaming, period.
Having said all that, I just checked some of the entries I made way back when, which I did with full write ups, my source, photos, and in one case I was in fact the business head of IT and provided that from my work email and a device on our business Apple ID even. And I'm positive those were accepted and on the map for at least 6 months while I was still there. Yet now I look and nothing, and they definitely are still in business at the same location. That's kind of a crappy. If Apple accepts user submissions but then blows them away from time to time during map source fusion say it could explain some of their paucity of data and would discourage more submissions from those few who bothered in the first place.
What I really hate are mall locations. I wish pin markers put the actual stores in the right portion of the building(s) themselves... hate parking on the wrong side of the complex to find out that I parked on the wrong side. Increase that to when the temperatures are more extreme (under 40F in the north or over 100F in the southwest).