>I would much rather be able to have things like personalised searches (which are identifying).
This wouldn't affect your accounts usability or features it would just delink your payment from your account. Same as paying for Mullvad with a giftcard bought on Amazon.
I don't really understand your first paragraph.
Privacy Pass would decouple each search from the account. I think it’s okay to have as an opt-in thing. But private payments should be the default IMO.