My thing is what exactly is that impact? How much of what they do is impacted by what their offensive line, receivers, and running backs do? And then they aren't even on the field for half the game. It's impossible to actually quantify how much of an impact a QB has on the actual end result. They definitely have the biggest impact relative to the other positions, but it's still not nearly a big enough impact to use wins as the biggest barometer of what makes the individual QB good.
At the end of the day, between the numbers and the eye test, Romo has Eli beaten in basically every way IMO. I'm not sure there's really an argument to be made for Eli besides just the "his team has won more in the playoffs", but even then, Eli's offenses have scored fewer points in the postseason than Romo's (obviously far more goes into scoring points than simply whose offense performed better, but I don't have the time to dive into every possession of every postseason game lol). The difference is that Eli's defenses have given up a full touchdown less.
And regarding your reasoning for why Rodgers is better than Eli, Romo also has a higher winning % too and has had a winning record as the starting QB 8 out of 9 years, versus 8 out of 11 years for Eli.