There are 3 times as many basketball teams as FBS teams.  Also in basketball, a single player or two can throw a team on their back and carry an otherwise mediocre team far beyond what it normally could accomplish.  Its not the same for football. becasue of the, a 4 team FBS playoff equates to something around a 20 team play off in Basketball.

A given 20 guesses, any expert should be able to pick the best team in college basketball.  The same goes for football.  While we all love cinderella stories, does anyone really believe that UCF is a better football team than Alabama?

The NCAA tournament is all about the pagentry and the "experience" of the tournament.  Most of the teams entering the tournament know they have no chance at playing for the actual championship.  Even Most fans have goals for their teams that are related to what round their team will reach, not whether or not they will win it all.

The CFP is about determining who is the best football team.  For that reason only a hand  Instead of the first couple of rounds of a 68 team tournament, football has a meaningful regular season, conference championships, and bowl games.  These are the equivilent of the first several round of the NCAA tournament.  These are how teams who have no shot at being champions measure the strength of their team and the success of their season.