Based on past similar deals, wouldn't have been remotely enough, assuming the Browns ever considered trading out of that pick. Unless you're saying they'd trade like four first rounders?I guess the plan was to use the Lions and Rams picks+ to trade up for Baker Mayfield.
I'm skeptical to begin with the Pats would ever trade the kind of pick bounty that it would've taken to get to #1 when the team sitting at #1 liked a top-flight QB prospect at the spot and didn't have a long-term solution at the position. Why would CLE trade out of that spot for anything but a ridiculous package, and why would the Pats offer it? From the Pats perspective, as much as they may have liked Mayfield (and do we really know they "loved" him because they met with him?), that kind of trade would nonetheless leave them still putting a lot of chips into a guy who hasn't played a single NFL snap and likely won't help you for several years. That's a pretty risky bet for a contender who - like every other team - needs help at several positions over the next 1-3 years.
I think it's more simple than that: the Pats were ready to move on from Gronk due to durability/contract demands/whatever and got a package they liked in and of itself, regardless of whether it would have secured them enough assets to get Baker Mayfield. And there's no evidence they had a preliminary agreement with the Browns contingent on securing the Detroit first rounder, or that the Browns even entertained such a deal.