Why are doctors so unwilling to run tests?

I had a similar experience recently with some stomach pain. The doctor wasn't really interested in why I had the stomach pain and just prescribed some anti reflux meds. Felt like it was just a guess a check approach.

The anti reflux meds didn't work, but my stomach pain did eventually go away, so it does lend credibility to just do the "first line treatment"/do nothing approach, but definitely frustrating from the patient perspective.

Most doctors haven't been taken to small claims court enough for wildly misleading, damaging decisions based on failed math or other educational basics.

Alternatively, "Why do I think tests are so valuable that doctors should order more of them?"