I feel like Bennett is a really important piece. Being able to run two TE sets is a nice luxury, and with Gronk's injury history it's nice to have a viable backup in place that can step in and reliably fill the role of a starting TE. That said, there's only so much money to go around, and you can't keep everyone.
I know he said he's excited to go into free agency as a SB champ.... but like
The Brandon Five mentioned, he also said a lot of other things leaning the other way. He said "you don't come here for the check, you come here for the championships". He also said something like, "some games, I only got one or two targets -- and I didn't care". He also mentioned that "some games, I'd be asked to help block most of the game... and Tom would come over on the sidelines and say, 'hey man, you're killing it out there, thanks for the help'". He said a lot of things that makes me believe he genuinely loves it here.
I'd love to see him stay but who knows. That said, it's not like the Patriots are the only contending team in the league. Maybe he could find a legit SB contender and pick up a huge paycheck. It's not like his only options are "win" or "get paid". I think NE gives him the best chance to win, but not the only chance to win.