Kagi is one of them.
[1]: https://help.kagi.com/kagi/faq/faq.html#fair-pricing
I recall a db service does that too long ago. Although I'm not sure if they changed policy as it's been a while.
[1] https://web.archive.org/web/20200522032356/https://media.net...
edit: and obviously reactivates after activity
I know it's not exactly a subscription service though where they were making money from me whether I used the service or not. It was just surprising to me that someone felt the need to develop a cancel user purging system at all.
This was mainly done for privacy reasons, so less data needs to be stored in the account (it also only uses a randomly-generated account number, like Mullvad), but honestly, we don't want people paying that don't use the service.
And you're right, it makes "making money" much harder, but also, feels more honest.
[1]: https://uruky.com
they had a whole webinar about it with all sorts of justification, although most of it sounded like mba-isms to me.
Not exactly a subscription since it's a stored-balance system, but still.