I don’t think 16 renders the season meaningless.
IMO, since the playoff was introduced, teams on the outside looking in look at the end of the season view their bowl games as meaningless. That’s why you see so many players opting out of bowl games.
Right now, there are literally only 4 teams who give a shit after January 1st, and there a only about 18 that care after around November 10th.
With a 16 team playoff, the battles for home field advantage and the last several playoff spots would be really intriguing.
That being said, 16 might be too many games. 8, or even 10 (2 teams get first-round bye) would be about right.