There are only a handful of players that are truly untouchable in terms of trade for many different factors. Star franchise players (most of the time) typically stick with one team for atleast their prime if not their entire career.
However, even some of the great players in the NFL that among the best get traded all the time. There are also players who have been solid throughout their career that have been on multiple teams, like D.J. Moore who will now be a member of the Bills.
When you look at what the Bills’ current roster is, there are a handful of solid players on both sides of the ball.