It's not irrelevant. It shows that Roma are a weak team. They're 4th in the Serie A for a reason. If you actually try to play a football game against them and play like a proper, big team, it shouldn't be so complicated to win against them.
Barca were barely the best team at home.
The better question is who did we dominate away from home in CL?
Sporting? Not really, mega lucky to get 3 points thanks to a hilarious own goal. Olympiakos, dud game, can't remember any serious chances created. Juventus? Another dud game in which we didn't dominate jack shit. Chelsea? Miracle we ended 1-1 and not with a 0-2 loss or so. Roma? Played off the park.
5 games. 2 goals, out of which one was an own goal and another a gift from the opponent.
The team had no right and no basis to get cocky coming after 4 away games in whcih they didn't even outplay Olympiakos.