Scouting information is useless if you don't have the resources to make a response
Forward scouting is always useful. If I see someone 6/7 turns out heading towards my planets, I can save up more resources than if they're 2/3 days out - hence my wall of Blackbirds. Even if I don't have the resources now, I can acquire them in that time - build small ships from my colonies and send to where I have a military base, bring back merchant fleets to scrap them for their steel. So I wouldn't say it's useless if you don't have the resources. Obviously it's better if you have a stockpile of resources so you can respond immediately, though.
