Yes to the above, and I did neglect to mention the possibility of simple usb renderers, not streamers, which means one can use server with non optimized usb port connect it to usb renderer which then connects to dac. The simple usb renderer has only usb in usb out, streamer renderer has ethernet or optical in, usb out. Also there are streamer/dacs in which case internal streamer of dac will provide the galvanic isolation, hopefully good power supply. This what my Okto Dac stereo did with internal raspberry pi. PS Audio network card does this, although differing opinions on it's efficacy. Playback Designs supposedly has nice implementation.
Lordmelton is running Aurender server, in previous post I questioned this as Aurrender only states in literature that port being optimized and being clocked. So it appears somewhat optimized with the clock, but still running directly off motherboard and getting power from the server power supply. So appears somewhat better than standard, but not what I'd call optimized.
While I've not researched this, I've heard of usb/network converters in which case one could make server work like mine with the two network ports, one for network input, one for output. This would also bypass the usb. So one can do this with the single network port with separate streamer by using network switch which then feeds streamer. But then optimizing this then becomes necessary, which means audiophile switch with good lps, more money, complexity.
So, what we have here is two levels of servers in regard to usb implementation. There are the non optimized usb servers, which are generally cheaper, these would include NUC's Raspberry Pi's, and non atx boards in most off the shelf servers, may be forgetting other solutions. So then, need to add streamers, audiophile switches or usb renderers to get optimal usb solution. Then there are the top shelf servers with usb optimization built in, no need for any add ons of any kind, these would be servers like Innuous Statement, Wadax, Taiko. There are also top flight servers made to be used with streamers, personally I like the Antipodes K40,41 here. I suggest best implementation for these kinds of servers is having a SECOND ethernet port, forget the usb in server altogether, many good choices for usb renderer/streamers. This is route I take.
Just to explain, atx motherboards are essentially made for MS Windows machine. The reason these aren't used is likely because of prohibitive cost to fully optimize. The off the shelf atx server would be unaffordable for vast majority. But then atx boards do have the ability to be the ultimate best server to my way of thinking. You can massively optimize every single port, you can run hugely powerful processors if dsp is your thing, you can have the absolute best implementation of power supplies for each and every critical section (atx boards have various voltage and amperage requirements for individual sections of computer). You can run Windows OS which some claim best, you can run Linux. So DIY atx server can compete, perhaps even beat the Wadax's and Taiko's of the world, although I would say that very tall task.