I listened to some CFB Podcast Bros talk about this. One of them made an interesting point. An expanded playoff keeps more people in the running for longer. It'll create opportunities for two 8-3 or 9-2 teams to play late season match ups with real CFP implications.There's two sides to it for sure, and it depends a lot on what era we're comparing (e.g 12 team era vs 4) and your personal sweet spot. For the 12 team playoff, we only have a direct sample of one, but I think it's pretty clear that 2 loss teams are in the discussion, and even some 3 loss teams in certain scenarios. Expansion will only make those more and more common, and the stakes for regular season games less. There was something special about top ten games before that I think is being lost.
I have mixed feelings personally. 4 was way too tight IMO and too biased towards what used to be the P4. Expanding from 12 though isn't going to get me to watch more playoff games, and it will make me less interested in the regular season.
The part that may get lame is the automatic qualifiers. I understand that some years going 10-2 or better in the B1G or SEC may be harder than the ACC or Big XII, but there will likely be years where the #22 team in the country is the fourth-best B1G/SEC school with an 8-4 record. Is that team better than a 9-3 ACC/Big XII school that finishes ranked #20?