BITD when I did mountain touring we did a fair bit of rear braking to prevent the front from overheating. I still remember the front rim sizzling when rolling through a puddle after a LONG descent.
On most of my road riding I set a small amount of rear brake while I do most ”active” braking up front. Basically I use the rear as a gauge. If the rear wheel begins to lock up, I know it’s becoming unweighted and that there isn’t much more braking to be had before going OTB.
Slick, slippery surfaces also prompt more rear brake use.