Hopefully this will signal a pivot in ad tracking and lead more companies to try subscription based services.
I highly doubt this. I suspect this will instead signal a pivot to products that are intrinsically "trackable".
It's important to remember that ATT doesn't disable tracking in its entirety, it only disables cross-app tracking. It's only harmful to your business if you are reliant on tracking users while they are not using your product.
Lots of products will continue doing fine - think about Google Search, where you directly tell Google what you want. There is not necessarily a huge need to track you while you are not using the product - after all, the product literally revolves around you directly telling Google what you want.
The products that will benefit the most are the ones that a) shows ads, and b) where the product's functionality intrinsically collects information about the user without the need to rely on third-party data.
Oddly enough FB's apps fit decently into this. Your behavior within the FB main app are still "fair game" as far as tracking goes, and FB shows ads directly in the app.
I am not quite sure what advertisers are complaining about. Facebook should still be able to track purchases of physical goods, since most of those will require an email address and facebook can use that to link up the sales.
Web site retargeting is not really affected by this. I guess people using shopping apps would be impacted, but a lot of those folks will be logged in and trackable. This article references "Most retail websites" but they are not affected by the recent change (ITP does affect them, but that is not new).
App downloads are probably much less trackable and that would definitely be affected.
I guess ads will continue to work about as well as before and then ad buyers will realize they can buy ads directly instead.