[As mentioned in a linked article, the commonly stated justification was to “lock in the juices”, which isn’t true, but it wouldn’t surprise me if food safety was the actual impetus behind that advice.]
I actually think there is an important element of truth to the idea that searing locks in the juices. This video discusses it.
The idea is that no, searing doesn’t lock in the juices that are inside the meat. However, the perception of juiciness is subjective and not just dependent on the actual juice in the meat. A big part of what makes you perceive something as juicy is how much it makes your mouth water, and searing does seem to make your mouth water a lot more.
I actually think there is an important element of truth to the idea that searing locks in the juices. This video discusses it.
The idea is that no, searing doesn’t lock in the juices that are inside the meat. However, the perception of juiciness is subjective and not just dependent on the actual juice in the meat. A big part of what makes you perceive something as juicy is how much it makes your mouth water, and searing does seem to make your mouth water a lot more.