I think you may be marginalizing what Everett brought to the Rams. The Rams weren't in a situation like the 49ers where any QB you plugged in would have success. The Rams couldn't find a QB. After years of retreads, they finally made a deal to shore up the QB issue and Everett provided it. It's not like the Rams were better at QB before or after Everett. Did any of the players that he lucked into ever do anything without him?
As far as Bradford, I agree that he had a tumultuous time with the Rams but he also had a couple of teams after the Rams that had talent and he still didn't produce much. With Minnesota for example, Bradford started out great but once he settled in, he and that offense really faded that year. Bradford was essentially the poor man's Alex Smith. Probably wouldn't cost you a win but ultimately, produced the bear minimum with what was available.
And, at the end of the day, one can't ignore the injuries and inconsistency. Bradford had opportunities on solid teams but couldn't stay on the field. The '13 Rams and the '17 Vikings teams weren't world beaters but they had talent and potential. And Bradford played well but couldn't stay healthy. So, even if one considers him better than Everett, Bradford would still likely have been hurt and not produced for McVay. Bradford lost his job in St. Louis, Minnesota and Arizona that way.
IMO, "better" has to include availability.
