I don't give a shit what address or phone number people think they're sending to, when they see my name on their iPhone, it's the wrong address.
The only reason my iPad even has iMessage installed is because people were sending me messages that got disappeared by Apple's abysmal policy.
Why is this so hard for you to understand?
Apple is the richest company in the world but for some reason their process for delisting your Apple ID from iMessage is a huge fucking joke.
There's no way this is not an intentional decision on their part.
It's literally impossible to send an SMS message to someone's Apple ID and it's not possible to send an iMessage to a phone number that's been unregistered from iMessage. Just because you don't understand how it works doesn't mean Apple is at fault. You cannot delist an Apple ID from iMessage, you can only sign out of iMessage on a receiving device. That's it. Anything else above that is your fault.
If you don't want to receive iMessages at all and don't want people sending them to you, sign out of iMessage. It's not that hard.
It's not a dark pattern. It's not an illegal anti-competitive strategy. It's a successful delivery of a message to the recipient address it was sent to that you're simply misunderstanding.