The difference from 4K or 8K is invisible at the viewing distance often used, but vinyl often sounds worse (hence vinyl is not real hi-fi).
If someone wants to characterize vinyl as "not real hi-fi" that seems reasonable, depending on what they mean by that.
For instance, if you want to have a hard bar for "high fidelity" which would be: "the highest current standard for fidelity"- digital - and anything that falls short of that is "not hi-fidelity" well that's fine as far as that goes.
I'm more interested in what someone will claim in terms of the implications for actual sound quality.
For example, take a best case scenario, an excellent record pressing from the same original digital master as the CD release (for instance one LP and CD version I have of Talk Talk's Color Of Spring). A good pressing can sound extremely close, almost identical, to the digital version. Now using the above criteria one could still just declare the digital "high fidelity" and the vinyl version "not high fidelity." But to me in actual sonic terms that's, as Axo put it, getting in to "the narcissism of small differences." I personally would still think of the vinyl version as "hi fidelity" in terms of the fact that playing it back on an excellent system (e.g. revealing/low distortion speakers) will produce tons of sonic information about the track. Certainly lots more than you would hear on a poor quality playback system with a digital source. That's why guests often are taken aback at the sound quality on my system whether I happen to play records or digital sources.
And this gets in to subjective assessment as to "how much better" the digital sounds. So taking again the previous example, if you have a super clean vinyl playback that sounds almost identical to the CD version...but now add in a few ticks and pops. What does that do to the "sound quality?" Well, if ticks and pops really bug you, really distract you, then it could be a serious downgrade in the sound quality. But if they don't, then a few ticks or pops are almost nothing consequential. Virtually all that same sonic information is right there to listen to, 99.9 percent of the sonic information coming out from the speakers is the recorded music. If you are someone who doesn't pay attention to a few ticks and pops, then you are still just hearing all that glorious sound and it would be damned weird to hear someone say "wow, now this sounds really bad!"
So we could listen to the very same comparison, both note any vinyl artifacts that occur, but still differ...reasonably...on it's impact on the sound quality in our listening experience.
I wouldn't begrudge anyone who is sensitive to vinyl artifacts. If it makes the experience suck for you, I get it. But someone else's assessment of vinyl sound quality as "low-fidelity" or "poor sound quality" based on their own sensitivity is neither here nor there for me: I just go with what I'm hearing and enjoying in my system, and in my own comparisons, mostly.