Motherboards used to be pretty standard fare: CPU socket, RAM slots, expansion slots, with differentiation coming from peripheral, BIOS, and stability/overclockability. Nowadays, CPU manufacturers have taken over a segment of the differentiation (chipset, or platform capabilities), so most of the differentiation is in aesthetics and branding. In this world, the grab bag of peripherals become a tradeoff, the cost per unit versus the percentage of market share it opens. Manufacturers have to increase their overall cost per unit in order to get access to the users who each have their own must-have peripherals.
Something like this moves things in the right direction by removing a lot of the overhead in motherboard manufacturing. If you look at the bandwidth required for todays peripherals, even in the most maxed out possible configuration, you won't be able to saturate an x16 PCIe 3.0 link: * 1.2 GB/s 10Gb Ethernet * 3.0 GB/s 6 SATA ports * 9.6 GB/s 8 USB 3.1 ports * 0.2 GB/s Wifi 6 * 0.1 GB/s Audio
The Utopia concept allows for multiple mini-PCIe blocks, but you could simplify it and just make the case one big PCIe device that handles IO.
USB4 goes a bit beyond that, with each port using up to an x4 PCIe 3.0 link, so you might want have direct access to motherboard USB4 slots (especially since this allows exposing integrated graphics cards via alternate mode).
I hope one day to see the motherboard simplified to a plug-in card which holds CPU socket and RAM sockets, and exposes PCIe and M.2 slots for connectivity.