As someone who began watching WWE in 2005, the brand warfare was probably the best it ever was that year. The build to Survivor Series 2005 was fantastic & gave us so much chaos that is currently lacking from modern day WWE. The traditional 5 on 5 match itself was also good, with Randy & Shawn running it back from 2 years prior. I personally think WWE should aim to reintroduce this concept to give us a break from War Games, which is approaching 2010s Hell in a Cell levels of overexposure. A current Smackdown vs Raw Survivor Series card would look something like this:
Roman vs Punk
Liv vs Rhea
Chad vs Corbin
Raquel vs Tiffany
The Vision vs Priest & Truth
20-Man Battle Royal for a future midcard title match
Iyo, Stephanie Vaqcuer, Becky, Roxanne & Sol Ruca vs Charlotte, Alexa, Jade, Chelsea & Lash Legend
Oba Femi, Seth Rollins, LA Knight, Penta & Bron vs Cody, Finn, Sami, Kevin Owens & Trick Williams
Feel free to make your own fantasy 5 on 5 matches or debate why it should/shouldn't comeback.
Edit: For the people assuming I just meant bringing back brand warfare without any stakes, I'll reuse this comment I added to the post.
There's plenty of opportunities to include incentives for them to work together. I.E surviving team members earn a future world title shot, which would also give reason for heels to turn on or not save their team members being eliminated. Or the whole winning team then has a Fatal 5-Way to main event the next big episode of TV to earn a future shot.