Does searing seal in the juices?

No — and this one is easy to check: weigh a steak before and after cooking, seared versus not. Kenji did, repeatedly, and the seared steaks actually lost slightly MORE moisture. A crust is not a waterproof jacket; it's a delicious layer of browned protein with cracks all through it.

So why sear at all? Flavor. That crust is the Maillard reaction at full volume — hundreds of roasty, savory compounds that unseared meat simply doesn't have. Searing is worth doing for its own sake, and that's reason enough.

The practical upgrade hiding in this myth: since the crust isn't protecting anything, you can build it whenever it's convenient. Sear at the end of cooking instead of the beginning — that's the whole idea behind the reverse sear, and it's why a reverse-seared steak has almost no gray band under the crust.

Here's the thing about kitchen myths: most of them survive because nobody weighs anything. When a rule can't survive a side-by-side test, drop the rule.