Theres pretty much no major content in 8k, only way itll become a thing is with some really good auto-upscaling, because even if there was content none of the streaming services would be willing to spend money to stream it to you, seeing as they already throttle or limit the bitrate while losing money, same goes for TV stations, it would be too expensive and physical media is slowly declining unfortunately.
8k might be a thing only for some niche gaming purposes in a few years, which is not what most TV are used for.
The pixel count difference between 8k and 4k is massive, but none of that matters unless there is actual content for it, perhaps TV manufacturers decide to jump on some AI buzzwords in an attempt to sell the 8k TVs with some advanced real-time upscaling to uninformed customers i dont see it taking off, but given that even 4090 lacks power to do that in real-time while running at full power and using 400W+ its like 2 decades away before it becomes feasible at an acceptable power consumption and cost.
8K was, is, and will never be anything. Definitely not a future. It's one of those nonsensical marketing things that was intended, or at least hoped to be the next driver of TV sales.
Now, they quickly found out that that driver is TV sizes, not 8k. In the next 2/3 years we will be seeing 100"+ TVs for under $3k. That is going to be the next major driver in display sales and tech.
I dont think there will be that many 100inch TVs, definitely not 4k as it has way too few pixels to look good at that size (44ppi), which is why 8k TV already exist, even past 60inches the pixel density is getting a bit too scarce at 4k, cant even imagine just how poorly 8million pixels would look spread across a 100inch panel. If you want to increase the size you need to increase the resolution along with it.
The 8k screens are niche because 4k is enough for the screen sizes that a majority of people can accomodate when it comes to space and budget.