I run 20 psi max in my tubeless 29er setup. 28 – 30 psi max if I’m running tubes.
That puts as much tire on the ground as possible for traction plus it softens the ride some for my old ass.
Doesn’t help much for rolling resistance but the tractional ( how about that for a made up word ) benefits are worth it. I run pretty beefy tires, Mountain king rear and Bontrager 4 up front. Big lugs, good traction.
We get a real mix of terrain and conditions here in the north GA mountains and this tire combo has suited me very well.
Riding position and technique are 3/4 of the game but ideal tire set up for you and the local terrain is the other 3/4 of the equation. ( dig that made up math! )
Ride on!