All of the time and energy spent on F&F could have been spent trying to bust straw buyers elsewhere - supplying guns to gangs in LA, San Diego, Oakland, Chicago etc...
But those operations wouldn't have had any more impact than your typical "XYZ law enforcement agency confiscate n-tons of drug-xyz, with an esitmated street value of n-dollars. n-number of suspects in custody"
The F&F operation however had potential currency to change public opinion. The angle was that American gun shops where arming the hated Mexican drug cartels with American guns. - Ipso facto - American gun laws were flawed and required fixing.
The theory that F&F was primarily conceived to be a lever to move public opinion is not far-fetched.
BATFE's bungling aside, those resources could have been used more efficiently to greater effect in other areas of the country, but those operations had no potential political currency associated with them.