I agree for the most part but they arguably have a top 5 QB, Goff isn't even top 10. An elite QB can win games on his own as we know first hand. You can have holes with a QB like that and it doesn't matter.
Look at Green Bay. They have Rodgers who is a top 5 QB and they win year after year after year. They don't win the SB every year but are always one of the better teams even with bad defenses they notoriously have had.
The big difference between winning regularly year after year is having an elite QB and the Bills have that.
Rodgers is a HOF QB. Once in a generation QB. He is in the Brady category. But even Rodgers, they did have a period in 2017 and 2018 where they fell out of playoff contention and had to retool their roster.
The Saints couldn't do stay consistent playoff/Super Bowl contenders with Drew Brees and Sean Payton. The Seahawks couldn't do it with Russell Wilson and once and a generation defense. The Colts couldn't do it with Andrew Luck. The Steelers couldn't do it with Roethlisberger. Rivers, Tomlinson, and a young defense was supposed to be contenders for years. They lasted like two. A lot of those teams had periods of being consistent contenders, but they usually only lasted 3-4 years and then they fell out of the playoffs and some came back with retooled rosters.
Brady and the Pats and, to a lesser extent, Rodgers and the Packers being contenders year and year out for a decade or more are the exceptions to the rule. The rule is most teams don't have more than a 3-5 year window of success.