I guess the Patriots could still be contenders, but it won't be the same. For 2 decades the Spurs and the Patriots were year in and year out contenders, backed by 2 very loyal and very talented stars (Duncan, Brady) and 2 of the greatest coaches of all time.
About 10 years ago I loathed both of those teams, but as this last decade played out I found myself cheering for them both. Seeing such excellence year in and year out with aging stars was amazing to witness. Saying we got to watch Brady win his 6 rings will compare to those who watched Jordan win his 6.