BoM is just a nice quality of life feature for the older residents amongst us,which have not trashed their old system stuff yet and want to reactivate some of it again.
The rest simply put won't use it nor care. It's not really that important IMHO.
It's more than that.
It's one tool more to aid us in optimizing content and reducing both mesh complexity and memory usage. Badly used, it saves 1-2 layers of your body that would otherwise double or triple your polycount and texture memory usage. Properly used it can save all layers and can be used to quickly and on-the-fly alter a texture. The possibilities are quite huge, people just don't realize what BOM entails and what it opens up. An extreme example: I could use it to split a body texture into several layers, taking a dragon as example, i could use a base color, multiple gradients, tattoos, markings, details, extra body details (such as bits and nips) and even a multitude of different scales variations (amount, density, color, size, area covered) and they all can be mixed and matched and combined infinitely, not to mention that with them being handled as clothing we could easily do extra things like recoloring them.
BOM is much more than just oldschool baking on mesh.