What goes into winning a superbowl is like what goes into baking a Gateu St. Honore... oversimplification doesn't begin to describe how bad of a process it is to look at the past 8 superbowls and say "well they didn't have a high paid RB so you must not need one to win". There are so many moving parts and pieces, that include even intangible things such as refereeing and luck, that one extra scoop of flour is enough to make the whole thing fall in on itself. The much less convoluted way to look at it is the Giants are better with Barkley than they are without him. Again, I don't see anyone disagreeing there on that simple fact. What that should equal financially I won't pretend to know. But again, that's not what I'm making a case about.
I agree with all of the bolded. But what makes it a bad decision is to pay an RB a big contact over multiple years. We all see that a team can draft a rookie in rounds 2, 3, or 4 and get 75% of what Barkley gives them now. And certainly more than what Barkley is likely to give them in years 2 or 3 of the contract. Instead, the money is better spent building the OL, DL, QB, WRs, and DBs. Yes, they're better with him *this year*, which is why they decided to tag him.
I don't know the Giants roster well enough to know what contracts are looming for them beyond '23, but I'll bet they'd rather pay an O lineman or D lineman whatever money Barkley would have gotten in year 3 of a new contract.
Yes, the last decade has been dominated by HOF QB play wrt championships, but that's probably not going to change anytime soon. And besides Brady and Mahomes, we saw a shell of Peyton Manning win, Stafford and Foles as well...and none of them had high priced RBs on the team. Look at least year's 14 playoff teams - how many of them had RBs with big cap numbers?