How can you really get to know a person? Ask to see per loyalty cards: https://www.theguardian.com/commentisfree/2023/sep/25/how-can-you-really-get-to-know-a-person-ask-to-see-their-loyalty-cards
If I showed you mine, you'd get to know me well enough. I have only one — from a chain which let me have it without my giving any personal data. That is why I judge it is acceptable to use.
The Boston subways and buses would let me pay a reduced rate because of my age, but then it would associate all my travel with my name and personal data. No thanks!