Why let the steak sit there getting cold?

It isn't getting cold — a rested steak loses only a few degrees, and carryover heat is actually still cooking the center for the first few minutes off the pan.

Here's the model: heat drives the muscle fibers to tighten and push their juices toward the center, like wringing a towel from the outside in. Cut immediately, and that pressurized center empties onto your cutting board — that gray puddle is flavor that was supposed to be in the meat.

Given 5–10 minutes, the fibers relax and the juices redistribute and thicken slightly. Then slicing releases almost nothing. Same steak, noticeably juicier — for the price of doing nothing.

The rest is never wasted time anyway. That's when the salad gets dressed, the pan sauce gets made from the fond the steak left behind, and the table gets set.