There's so much room for improvements on affordable 4K sets it's kind of funny to think that we're expected to clamor for incredibly expensive 8K sets that don't even fully address the current shortfalls in today's high priced 4K TVs.
Brightness, contrast, and more LEDs being used in wide array backlit sets, are all things that if improved on can make a noticeable difference in affordable mid-range TVs. That, and including the top of the line image processors in model lines that include sets sized for the desktop.
And of course there's the two biggies of having sets that fully support the HDMI 2.1 specification, and can give us a refresh rate that supports 120 fps with all the bells and whistles like HDR also enabled, and which support VRR, and FreeSync. A display port connector would also be nice.
Just read any well written review of good mid-range 4K sets at around 43" inches in size and it immediately becomes apparent that there's a lot that can be done that could take those sets from being very good to being awesome.
I'm using a RTX 2080, and even if I upgraded to nVidia's highest end card of its next gaming series, let's call it a RTX 3080 Ti, I very likely wouldn't be able to game AAA titles of the last few years at 8K and 60 fps, let alone whatever games were just coming out, and would be coming out in the next few years following. Edit: Nor would 30-60 fps with a variable refresh rate likely be in the cards, imo. At least not for new titles, and upcoming titles.
By the time we got cards that made AAA games at 8K playable, today's 8K panels would likely be both improved on, and greatly reduced in price. With the advent of 4K sets at somewhat reasonable prices we had a video card like the GTX 980 Ti that was arguably overpowered for 1080 panels with the games of the time, and we had a lot of 4K video content on the horizon. And then the GTX 1080, and 1080 Ti, really made gaming at 4K highly plausible.
Today's situation is a bit different in important ways. The movie studios don't have a vast library of content that should get remastered in 8K, nor have 8K digital cameras been used all that much in recent films. A lot of the world isn't set up to get 8K cable broadcasts of sporting events.
Conventional wisdom is going to be harder than ever to shift to accept this last boost in resolution as having solid benefits for the average customer. Prices will have to come down a lot, and 8K content become a lot more common, before people will just say "Better to have a 8K panel and not need it, than to need a 8K panel and not have it".
But what do I know, maybe there will be big improvements in how sets scale, and even 4K content will look noticeably better on an 8K set.
Edit 2: Another point to consider is that with 4K we had UHD blu ray players, and services like Netflix and Amazon come around to support transmitting video at 4K. We recently saw news that Samsung was getting out of the blu ray player business, and we need to think if 8K blu ray will take off any time soon, and at what prices. Given how both Netflix and Amazon aren't exactly generous with the bitrate of 4K content, I'm not optimistic with how they'd handle 8K. Though if 8K content was considered a boutique item, and priced accordingly, then Amazon might think it wise to give some bang for all the bucks they were charging. With Netflix, I just don't know.