First, the x99 platform its not for the mainstream, if you need more than 4 cores x299 its useless, there are atx and eatx x99 motherboards with more than one m.2 x4 slot, x99 its not aged its just not mainstream, for example a x99 deluxe II with a 40 lanes cpu, can give you enough room for 3 gpu and a m.2 slot full speed configuration with type c usb and wifi, the full package, even thunderbolt connections.