I want new computer...

Good.  So the technology exists, but there is not enough of a market for a motherboard company to spend the time making one.  That's fixable.  It's called Kickstarter.  Raise $100,000, then partner with a motherboard company to design and print off 100 of them.  I may just do that.
 
There are 1000 other studio users who are looking to get into the Threadripper craze right now, but what stops someone like me is the fact that I have zero confidence that a new computer will let me use audio freely and confidently.  Graphics cards, USB3, RAM, and PCIe slots enjoy this luxury.  It is now audio's turn.
 
What I mean is this:
I have a Yamaha MOX that can stream usb audio
I have a Korg M3 that can stream Firewire audio
I have a mixer that can stream usb and Firewire audio
I have three Zoom mixers that can all stream usb audio
I have web cam that can record usb audio and video and
a Camlink that can do the same.
And I have the motherboard audio.
 
As it stands now, I can only use one or two of these devices at once without running into all sorts of problems.
I want to be able to use them all at once, or at least the first three all at once. 
 
Some sort of control panel that manages all these devices in one place (like the asio4all panel does) would be a must.  That might have to be another Kickstarter.
 
I think this is probably impossible...but I wouldn't know for sure.
 
 

I just finished working on an article in which I was running the same three audio functions; Dante Virtual Soundcard, Midas DN32-USB, and a Dante AVIO-USB in both macOS and Windows 10.  
 
My machine has a firewire Echo AudioFire Pre8 and 10 USB devices; two are audio.  The constraints of Windows ASIO and Windows Audio Device made changing between these a rather clumsy and error-prone situation. As you have correctly stated, it's drivers; specifically multi-client drivers and the sound subsystem architecture. 
 
Although I've never used it, it seems that the VoiceMeeter product [ https://www.vb-audio.com/Voicemeeter/ ] is your best way forward for doing what you want in a Windows environment. 
 

Market determines devices and availability.  Just as Jim Roseberry stated about motherboards is also true for us Pedal Steel Guitar players.  Probably 10000 to 1 (maybe larger) ratio for 6 string guitar players to Pedal Steel Guitar players. None of the mass market musical instrument companies (e.g. Fender) make a Pedal Steel Guitar, its all small boutique builders.   There are very few amps and other devices designed specifically for Pedal Steel Guitar.  We have to use general "guitar" devices (e.g. effects processsors and stomp boxes) and many of those are not very good for use with Pedal Steel.  Peavey and Quilter are the only two mass market amp companies that make an amp aimed at Pedal Steel Guitar (I have a Quilter "Steelaire" rack amp).  I use an old POD X3 for effects only (no amp modeling) but had to develop my own effects chains as the built in factory effects were all useless.

From the Banana Manual:
Looks like you can set two (of 3) outputs to different sources,
one ASIO (mixer, Sound Card) and one WDM (onboard computer audio)
https://screenshots.firef...9oExo/www.vb-audio.com
 
The next step is to turn every single device I have on, and see what shows up in this list:
https://screenshots.firefox.com/POqYMMsXod08oK6E/www.vb-audio.com
 
I'm reading the manual before I install anything, but this is looking good so far.
I really want to ask JunkieXL about this...

It's almost easier to input audio from older synths into a mixer or interface and record the midi channels. There's something to be said for hardware midi routing too. You could record audio and have a midi track at the same time.
CbB has sysex so it can speak to the older hardware.
 
Probably not what you wanted to hear, but music production has been concentrated on routing ITB for some time now.
 
The industry is focusing on the user who uses one or two input devices. Most stand alone usb recording devices are designed primarily for dumping audio that was recorded on location.
 
I know this isn't what you want and unfortunately you are in the minority. I don't think a dedicated MOBO for audio would sell because it would cost more and the market for it would be very small.