If the ACC is a part of the system and everything stays as it is now why would Clemson leave for the SEC? That would be a whole lot harder road to the playoffs than the the ACC.
Here's what happens now.
SEC has Alabama, Georgia, LSU, Auburn, Florida, Texas, & Oklahoma. All programs that have won/competed for titles the last 20 years. Then you have programs with big money and fans like Texas A&M, Tennessee, & Ole Miss who recruit well. Not to mention SC & Mizzou have had some decent teams.
Big Ten? They have Ohio State, Michigan, Penn State, Michigan State, Wisconsin, & Nebraska. All are big time programs with money, history, recruiting, success, etc. Not the SEC, but pretty close.
Now you have NIL and huge TV Deals. Players want to be on TV. Recruits want to play against the BEST OF THE BEST. All of the money and advantages will be going to those conferences. The money will be HUGE. It's going to get to a point where the big conferences are going to be like the NFL AAA system. So it comes down to if Clemson sees the ACC losing relevance and if they think they can be an AAA level team in a AA conference, or if over time it will hold them back from competing against Alabama?
Look at the 2019 season. Clemson was the ONLY ACC team that was ranked in the Final Poll.
2018? Clemson was ranked and the only other ranked team was Syracuse who had a fluke year.
The new super conferences will make it where the SEC will move to 9 games. There will be less chances for them to play big time non-conference games. Ever since FSU has fallen off, there hasn't been a big time ACC game for Clemson since the Lamar game in 2016. Last year we saw how big their games against Notre Dame were, so that's priority #1.
They may have to look and wonder if the easy road to the playoffs will be financially worth it? Will games against UNC be the big time matchups to get their players NIL money? As of right now, the ACC is at a point where they're pretty much what sUcKs basketball was in the SEC for years. But basketball isn't as dependent on money/recruiting.
If the Big Ten starts making moves or say USC & Oregon contemplate a big time move? Then the arms race begins. If Clemson & FSU start seeing that kids in high school only think the SEC and Big Ten games matter and they don't care about Clemson's "big game" with NC State, that will change things big time.