For the same reason the advertising industry came up with "legitimate interest" as a fig leaf which now apparently includes serving personalized ads based on an

For the same reason the advertising industry came up with "legitimate interest" as a fig leaf which now apparently includes serving personalized ads based on an ongoing profile built of you... you know... the thing GDPR was explicitly supposed to make opt-in and forbid as a default. Telling advertisers they can't track you is like telling a kid not to eat the candy. They can't not do it.