Why were seven men chosen to serve in Acts 6?

Answer: Widows missed food distribution

Grecian Jews complained their widows were overlooked in the daily distribution of food, so seven men full of the Spirit were chosen.

“In those days when the disciples were increasing in number, the Grecian Jews among them began to grumble against the Hebraic Jews because their widows were being overlooked in the daily distribution of food.”— Acts 6:1 (BSB)