For the typical use case (building a highly customised, target specific image for a pre-defined applications), what’s the main advantage of using Yocto over Gen

For the typical use case (building a highly customised, target specific image for a pre-defined applications), what’s the main advantage of using Yocto over Gentoo (eg: creating images with Catalyst)? It seems that they’re both well catered for that goal, but Gentoo really is designed for you to dig in deeper if you want (rather that trying to abstract everything away).