So, the basic question is: should slots go cable, or cables go slot? Evidently evolving the current hodgepodge of mixing both doesn't seem very sensible.
While I think slots are preferable in many ways, they really are a bad fit for the basic flexibility of PCIe lane allocations, causing all kinds of underuse or overprovisioning that is turning costliner with each generation.
Clearly using cables for each set of 4 PCIe lanes CXL style makes a lot more sense, especially as it allows for very precise trace lenghts using the 3rd dimension... at the cost of perhhaps even pricier connectors.
But mostly they'd allow to allocate those precious lanes wherever they are actually needed instead of tieing them to a slot, that might be covered by a GPU far too wide or need less (or benefit from more) lanes than a given slot provides.
Of course mixing a few lines with hundreds of Watts and hundreds of others with tiny voltages over anything shared is always a challenge for any single form factor that might have started with 5 Volts and 5 Watts on NMOS, so some functional and physical separation is dictated by laws of nature.
Asus here obviously went for the better looks, but I'll freely admit that this would be the very least of my cares so as far as I am concerned they have gone in the wrong direction here.
But then few things have been as aggravating, as difficult to diagnose and fix as cable errors and defects, especially when they creep in on you as you re-arrange things and known-good configurations suddenly fail...
Robust, flexible, reliable, high-performance and cheap never seem to mingle easily...