Did you mean searing as in sealing the steak early in the cook? Because that's an old myth debunked long ago. (Honestly, look it up, it actually leads to greater loss of moisture and weight when tested due to the different cooking times.)
Or did you mean resting? A VERY important stage often skipped by too many restaurants here in the UK. But who can blame them when the general public in this country are actually stupid enough to complain that their steak isn't served pan hot after resting!!! (Believe me, I've had it too many times... We still rest them though, we just rest them under mild heat lamps.)
Honestly, I think it's resting that gets skipped most often in this country, resting IS proven (unlike sealing) to allow the juices to redistribute amongst the fibers, leading to a much more tender steak when it's finally cut into.
If you want to try for yourself, get 2 good quality, thick, identical (as possible) fillets, pre heat a pan nice and hot, do absolutely nothing fancy, just whack both steaks in 4 minutes (ish, depends on thickness) on each side for medium rare. Then, when cooked, eat into one straight away (or you could just cut the first one up if you don't want to eat it straight away, I 'think' the effect will be the same) whilst you loosely cover the other in foil and leave to rest for at least 5 minutes, 10 minutes or more is even better.... The difference between the two will blow you away... (And sorry, but you just ruined steak number 1)
If you're ever served a steak in a restaurant that looks cooked, but isn't red hot, don't send it back, enjoy every mouth full, the chef that just cooked for you cares, a lot. (And that's rare in the UK, no pun intended.)