Opening the book…
Salt needs time to do its best work on meat, and the last-second sprinkle wastes most of what it can offer. Salt applied ahead first draws moisture to the surface, then that moisture dissolves the salt and gets reabsorbed, carrying seasoning deep into the meat and leaving the surface drier, which is exactly what you want for a good sear. This is dry brining, and it seasons throughout rather than just on top, while also improving browning and helping the meat hold onto its juices. Salt slapped on as the steak hits the pan sits on the surface, seasons only the outside, and pulls out moisture at the very moment you are trying to build a crust. A little foresight turns the same salt into a far better result.
Salt meat well before cooking: a thin steak or chicken pieces at least forty minutes ahead, a thick roast the day before, and leave it uncovered in the fridge so the surface dries. Use more salt than feels comfortable for a big cut, since it has to season a lot of interior. Pat the surface dry before it meets the heat, because a dry surface browns and a wet one steams. For small or thin cuts you can season a bit closer to cooking, but even then earlier is better than the instant it hits the pan. Let the salt and time do the work you would otherwise fail to do at the last second.
If you truly have no time, salting immediately before cooking still beats not salting, so do it and move on. Very thin or delicate cuts, and some fish, can turn spongy if salted too far ahead, so season those shortly before. And already-brined or koshered meat needs little or no extra salt.