Sports fans in the US long ago agreed that they prefer playoffs to determine their champions, rather than regular seasons. We've had plenty of discussions here over the years about what the best way to crown champions is, but the US fanbase likes its playoffs, and the leagues like the money that the extra games generate.
For actually crowning the best team, I like the system the european footballers use: you play everyone home and away, the team with the best record is the best team; they are the champions. That seems pretty straightforward and most likely to identify the best team for the season. But it can also lead to less exciting games at the end of the season (although promotion/relegation, and qualifying for the the Champions League and Europa League help), and it only works where you can make the number of teams and games match up correctly.
The old system in baseball: play everyone in your league, then the best team from each league plays in the World Series. But then the leagues got too big, so they added the League Championships. Still pretty reasonable, and playing 5-to-7-game serieses continued to allow teams to use their depth--which is key to a baseball season--to determine the champions. But once MLB decided to add the divisional serieses, it decided that making money on the playoffs was more important than excellence in the regular season. I understand both the financial incentive and the desire to keep more teams in the running later in the season, but the current baseball format--I think--just isn't very good for crowning the best team.
The NFL is probably one of the most competitive leagues in the world, parity-wise. And its playoffs system also values making money over the regular season. But at least the argument for the number of teams in the playoffs is better because the season doesn't lend itself to the European style to sort out which the best teams are.
CFB is just a mess for that. So, sure, have a playoff to generate a bunch of revenue and figure out what team has the hot hand at the right moment. Why not?