I think a common name for the shape is Dreadnaught.
Saw a youtube vid from a cat designer who talked about it lowering the hydrodynamic drag caused by the water that climbs up the stem before dispersing.
Not an issue if you lift the bow out of the water scow style.
For multihulls they are used to increase buoyancy in the bows to lessen the chance of pitch poling.
I think the benefits are less for a monohull. I remember reading one of the designers of the VO65's saying it was more for style rather than practical benefit on those boats.
That is more appropriate to this thread than you might think. The first of the sail assisted freighters built by in Japan was 26,000 DWT bulk carrier called Usuki Pioneer. The 1983 designed ship was also the first ship built with a long thin bulbous bow, as opposed to the fat bulb designs that had been in use for many years.