Is there any evidence that acupressure is better than pain pills for controlling fibromyalgia pain?

No. Accupressure should be used as adjuvant to pain medications, as well as massage therapy, water aerobics, and healthy lifestyle. They should all be complimentary.
No. Since the cause of fm is not known, there is no standard treatment. It is generally accepted that it is not a good idea to use "pain pills" (if you are speaking of opioid narcotics) in the treatment of fibromyalgia. There is no "better than", it is whatever works for you, but i would think that any reasonable and safe modality other than pain pills would be "better" for the treatment of fm.