Would rule based Bitcoin spending be useful, or is this dumb?

Hi Bitcoiners, I’m genuinely curious and not trying to shill.

I’m thinking about a service where you can keep buying and holding BTC, link your existing credit card, and set simple rules around spending.

For example, let’s say I only want to sell Bitcoin if I’m up at least 10%. If I buy coffee with my normal credit card and BTC is up 10% or more, the service could sell a small amount based on that rule.

If BTC is down, flat, or below my rule, it doesn’t sell.
Another version could be month end. Instead of selling after every purchase, it looks at the credit card bill and sells only if my rules are met.

The idea is that I can keep using my existing credit card and still get my rewards, but Bitcoin only gets sold when I choose the conditions.

Do people here already do something like this manually? Are there services that already do this? Or would most Bitcoin people hate this because it involves selling at all?
Thanks, genuinely trying to learn.