Well he had a first round pick in Brandin Cooks, now has a top tier WR like Michael Thomas to throw to, and also played with Jimmy Graham who put up quality numbers with Seattle.
As is normally the case, the real answer is in the middle. There's not a single QB in NFL history who has produced without quality talent around them. That includes Brees, Brady, and any other QB the ignorant fans think just make receivers look good.
My point overall with to dismiss this notion that teams that have highly paid QBs don't need to use quality draft picks on receiving targets around them. The Saints have a very highly paid QB, and they've used a 1st (one they traded up to get) and a 2nd on receivers in recent years.
The top 3 receivers on Green Bay... all 2nd round picks. That's called making a high investment in the position.
Well, to be honest, Brees also had Marques Colston - and made him a hug success - who was a 7th round pick - and Jimmy Graham was picked 25 spots after our Ed Dickson... If you analyse the receiving corps Rogers and Brady have been throuwing to, you'll also find mid- and late round picks mixed in with the early round ones. Investment is one part. The second part is grooming the talent you've acquired, the third part is putting the groomed talent into an offensive scheme where they can be utilized to their strength, and the fourth paret is a QB who can execute said schemes. I don't think the question whether Flacco is on par with Brady, Brees or Rogers should even come up really, the answer is so obviously no. But he doesn't need to be. He is easily good enough to lead a successful offense if he has the guys, gets the necessary pocket time, and an OC who can create an offensive scheme and playbook which utilizes the offensive staff to their strengths. The main problem, I think is with the latter. And I've been more and more suspecting the WR coaching staff also fails to properly groom the drafted talent - but that's only a suspicion, of course...