As a Bills fan, unfortunately, the window of opportunity is closing for the Buffalo. It may have already closed. They were one of the oldest teams by average age in the NFL last year, especially on defense. They cut Jordan Poyer and Micah Hyde and lost Tre'Davious White to an Achilles injury and then free agency. Matt Milano is recovering from an ACL injury at 30 years old. The DL is just OK.
Offensively, their best receiver is a second-year TE after trading away a malcontent in S. Diggs. Curtis Samuel, who I actually like, is perhaps their most sure thing at the WR position, but behind him, it's rough...a bunch of has-beens and never-weres (or at best, never-have-beens-yet). James Cook is perhaps an above-average RB whose touches will need to be monitored due to his size, but he is also a receiving weapon that affect the game in a number of ways.
All that to say, Josh Allen may have all the physical skill in the world, but his best years may be spent on a team looking to revamp itself at a lot of key positions. He has a good o-line, but he will have to elevate the play of his surrounding weapons or hope the Bills can add a true alpha WR at some point. Maybe Keon Coleman becomes that. Maybe they add Tee Higgins in the offseason.