I think his glum, taskmaster attitude and deep football knowledge fit in great with the culture of New England. For every success like Belichick in New England, there are 25 others that fail. No one doubted his chops at running a defense but once he had Brady and was winning, players would put up with the no fun, do your job, ethos. Once they stopped winning, and players started making a lot more money in the last few years, the act tired. Every draft he had to find these small school diamonds to prove how smart he was and after a few terrible drafts, the talent level sunk as they couldn't replace the veterans from those Super Bowl teams.
He's a legendary coach but he's not a great coach forever. To succeed in college football in 2025, you need to be young, hungry and willing to work yourself to death and I don't think he is prepared to do that anymore. Greg Robinson's Syracuse defense had a schematic advantage over the competition and the scores and tape look a lot like what UNC is going through. It's about the players you bring in and how you develop them and he and his staff know very little about that. Only question is whether they dare run it back for a second year of this dumpster fire in Chapel Hill.