Why YSK: When you cook meat, any water on the surface must first evaporate before much browning can occur. You want to get as much of a Maillard reaction as possible in the limited cooking time you have before the meat reaches the correct internal temperature. Removing the moisture first means that the heat of the cooking surface isn’t wasted on evaporation and can instead interact with the meat to form the complex sugars and proteins of the Maillard reaction.
Empirical evidence suggests that it takes many hours for the center of the steak, the part that matters for doneness, to rise any appreciable amount.
Drying the outside of your steak is good advice because your can see the results. The same with brining because you can taste it.
If your technique is otherwise good whether that’s low/slow or hot/fast then “letting it warm up” is just bunk advice.
Another note is that if your cooking set up can’t crank up high enough to get a good sear fast then you may benefit from the center being cold to start with to give you more time to develop the crust.