In a recent conversation with a neophyte millenial shooter, they expressed great disdain for the "cup and saucer" grip. For those aren't familiar, it is a shooting grip used for handguns, where the support hand wraps around the bottom of the strong hand. This was the popular technique for many decades in police training and even saw use in US military instruction in the 20th and 21st centuries. While it isn't the preferred grip of modern instructors, it certain has merit. It is a very safe way to operate a handgun.
Cup and Saucer grip
Most injuries I see at the shooting range are due to operator error. The most common among these is what is often called "slide bite" from shooting semi-auto pistols with an improper grip. If your weak hand is wrapped around your strong hand, it is very easy to wrap your weak thumb around the grip. This is fixed with a "Thumbs-Forward" grip, but ergonomically it's pretty comfortable to wrap that support thumb around the grip. This puts that thumb in the way of the slide when it moves, which can lead to a nasty cut.
A cup and saucer grip keeps the thumb well away from any dangerous area on a semi-auto pistol.
Thumbs-Forward grip
Now if you use the thumbs-forward grip with a revolver, this can cause it's own problems. There is a space in between the front of the cylinder and the rear of the barrel. Pressure, hot soot, even bits of lead or unburnt powder are launched sideways from this gap. If you have a body part in the path, it's going to sustain damage. A thumbs-forward grip on a small revolver can put a thumb in this space. For calibers like 38 special you'll just get a bit of a burn. For hot magnums you can actually lacerate skin or even cut part of a thumb right off. Here is a video using chicken wings to demonstrate the damage that can be sustained.
A cup and saucer grip keeps the support hand well away from the cylinder gap on a revolver.
Is the cup and saucer grip the best for accuracty, recoil control or fast follow up shots? Probably not. But it is a very safe grip and it has value for new shooters because of that.