Yeah, other contemporary round stadia like Shea, Three Rivers, the Vet, Busch II, Astrodome, Kingdome had box seats fill in area around the infield, but Oakland left it very open.
Your mention of Candlestick reminds me that on one visit to SF circa 1993, I stayed at a small hotel I think on Bush St near Chinatown. Around 5pm, as I passed the front desk on my way out to the street, the lady at the desk saw me carrying the rolled up blanket from my room and immediately said, "Going to the Giants game, huh?" Yep, I was.