So if i wipe my old pre iOS 15 phone and sell it to someone else, they cannot activate it? As a user who buys such an old phone i would expect grave security h

So if i wipe my old pre iOS 15 phone and sell it to someone else, they cannot activate it? As a user who buys such an old phone i would expect grave security holes. But not being able to use the phone at all is harsh. Planned obsolescence?