make their own schedules and can intentionally schedule weak opponents if they want to.
The black and white method of the NFL works because of how small they are (in terms of # of teams) AND more importantly their schedules are 100% made for them, so in theory (while luck of the draw can change things) everyone should be playing schedules with similar levels of competition
You can never get that in CFB, which is why allowing 16 teams in, to help mitigate the margin of error with subjectivity, is the right move