But you can see the difference between the WW11 and mid 50's super heroes and the Modern Age super heroes being so incessant and relating to the Public? Before that, the public were basically on their own in the Monster Age, with the previous super heroes you mentioned disappearing. I'm not familiar with the First Line, so were they written about in the Silver Age or before, or, were they retconned into the past later?
The effect of super heroes in the Sliver Age was that there was no physical war about then, (maybe a Cold War), so the super heroes had to justify their existence, and, begin to make the public dependant on them. What I saw was this vacuum of super heroes before the Silver Age, then they emerged in such proliferation as to take over the world, with their selfless acts. The future shock to the Earth 616 was shuddering, but didn't get to exhaustion till Civil War. The emergence of the Silver Age SH's was terrifying as well as exhilarating, because even though they were monsters, they were familiar, because they came out of human society. The SH's forged a new name for itself in the future world post-WW11. It was a defining event in the MU because now SH's could act out in the open instead of just be secret service personnel. They were holiday super heroes. SH's who didn't have a world war to define them, but a "civic" war against the super villains, who also defined the SH's.