Considering how important an Apple ID is, this is kind of scary to be honest.
I have had iPhones for more than a decade, and I never leveraged any "feature" of having an Apple ID on any of them.
I've never bought an app or spent money on one, and I don't use iCloud, so the Apple ID for me is literally just a gateway to downloading free apps that I can always redownload with another one.
You can't even wipe the hard drive and reinstall macOS without access to the associated Apple ID. This is a good measure to dissuade thieves from wanting to steal Apple devices, but it is a terrible measure from the point of view of a user who has lost their ID.
I said "if your device".
**IF**
Is it difficult to understand?
If it isn't associated (with "find my" turned on) there's no issue. If it is, and you lose your apple ID, you are SOL. Turning on "find my" with an associated apple ID is the same as making Apple the only entity that can truly control and own your computer. You can no longer reinstall macOS without your apple ID if there's an issue.
In fact 98% of the revenue on apps come from free apps.
Without being signed into an AppleID you cannot install free apps either. And if you install then sign out, you're also blocked from updating the free apps.