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.

Generally no. Ground beef doesn’t have a “surface” the same way a cut off meat does. As meat cooks fibers (can’t remember if it’s the muscle of the protein fibers specifically) contract and squeeze out water. In ground beef the water will be escaping every which way. In a cut of meat more of that water has a better chance of staying within the piece.