Rating-wise, NFL has more viewership than College Football. I think it is a very fair and accurate comparison.
NFL's Week 1 and a wild week in college football spelled another big weekend for pigskin TV ratings. Plus, notes on the WNBA and U.S. Open.
theathletic.com
I am not sure why you would call it "less" popular. College Football is literally the only team sport that I can think of without a playoff historically (at least until the recent 4-team playoff).
Even other levels of football: High School, Lower Divisions of College, etc. have playoffs.
I am sorry, the anti-playoff argument is running out of steam fast.