For me at least, the appeal of these is to get high-quality miniatures of WotC IP stuff—but that's a strong enough appeal that I'll be buying at least a few of them. For example I won't be getting any Frameworks orcs because as others have pointed out, there are much cheaper, comparable options available elsewhere, and I don't need my orcs to precisely match the 5e Monster Manual art the way these do.
But I'll definitely be picking up the beholder, the mind flayer, the drider, and probably a couple of copies each of the dwarf cleric and human cleric (shields with bas-relief holy symbols of Moradin, Ilmater, and Kelemvor are too cool to pass up). If I like them well enough, I could see springing for a few other monsters where the 5e WotC version is more visually distinct from the various non-WotC options, such as ghouls, trolls, and stone giants.