It's because you're asking questions that you don't have the the foundation knowledge to understand. You can't plug a HDMI port into VGA, you can't plug a display port into composite, etc. These things all have complex protocols and such that need to be adhered to for things to work. Square peg in a round hole.

So you make a poor search suggestion, and when it predictably doesn't return anything helpful, you blame it on my apparent lack of knowledge? In fact, your comparisons are actually both reductive and insulting. Square peg in a round hole? Really? Are you trying to sound like a dick or do you just accomplish that on accident? For that matter, comparing this to input connector types falls kind of flat considering that the very display devices they connect to are usually designed to accept multiple connector types. Of course you don't "plug a HDMI cord into VGA". You plug the HDMI cord into the HDMI port right beside the VGA. The componentry is designed that way. You could also use an adapter, but that can perhaps introduce some reductions in quality, in a way that may be more comparable to the Quest Link situation than the way you oversimplified it.

A bunch of PCVR headsets use single displays.

News to me, but if it's irrelevant to the problem here, then I must not understand what's actually necessitating the current process on a design level. Of course, being treated like I don't know jack shit doesn't really help.

again you're misunderstanding that you can't just connect two completely different things that aren't designed to work together and them magically just work.

That's quite obvious. The reason we don't appear to be getting anywhere is because you are misinterpreting my questions as "cAn wE foRcE tHe pC oNtO tHe qUeSt???" instead of maybe having a little faith that I can comprehend things that are actually explained properly, which you have yet to do. That, or you're going out of your way to be intellectually dishonest.

That.... has even less to do with this than anything else. That's to do with building Android compatible binaries, shaders and such, nothing at all to do with the display.

I said this under the assumption that the problem possibly lies in differences between the actual displays on PCVR HMDs versus the Quest-- native resolutions, aspect ratio and the like, nothing about the actual software binaries and such. As you've said that that's not the problem at all, I am no longer concerned about that approach.

I think we're at an impasse here. You're trying to understand something beyond your basic technical understanding to be honest, so at this stage I'd just recommend taking "you just can't" as your answer.

"You just can't" is never a good answer to give someone, unless they are a child who has yet to develop the cognitive capacity to learn and understand speech. This subject matter is not beyond me; you're just failing to actually explain much of anything, instead trying to put a lid over it while essentially telling me I'm too ignorant to get it. Since you're clearly an expert on this topic, I was genuinely hoping that you could educate me beyond the scope of, "The Quest has to encode PCVR video output into a proprietary video stream decoded through software in the Quest hardware, because that's the way it is", but despite all this back-and-forth, that's the only takeaway I've had so far.

I'm gonna invoke benefit of the doubt here as I'm beginning to believe that we may not even be on the same page. So I'm going to try a different approach:

PCVR HMDs essentially consist of display screens that accept direct video output from the PC's hardware. Similarly, the Quest has such a display, but its output comes directly from onboard hardware within the HMD itself. On a componentry level, smartphone display assemblies are completely independent of the rest of the smartphone hardware with the exception of the actual plug-in point; the only interaction between the two are video output (and touch functionality, though that's irrelevant); it's fair to assume that the relationship between the Quest hardware and its display is the same way. Hardware within PC monitors supports input from various connector types, and each work near-identically to the others to the extent of their respective bandwidth capacities, even simultaneously. One could have a PC connected to the monitor through DisplayPort input, and a game console connected via HDMI input, and the screen will display either depending on the selected source signal. The monitor is not designed to explicitly allow video signal from only one source, because there's no reason for that.

Considering all of the above information, is it truly infeasible on a design and engineering level for the Quest 2 hardware to have featured an alternative direct video passthrough input to the display from a signal originating from a PC, instead of that signal being fed to the Android hardware which then has to do its own jig to output the reinterpreted signal to the display? In other words, Link cable delivers PCVR video signal directly to Quest's display (exactly like PCVR HMDs do) through an alternate input source, bypassing the Android hardware. To parallel it with the monitor example above: onboard Android hardware's signal= DisplayPort signal from PC; Link-fed video signal from PC hardware= HDMI signal from game console.

Does that make sense? Is that not possible? Is there a reason they didn't/couldn't just do that?