Publicly the cinema industry doesn't release that many 8K movies, but at least there is a list.
https://www.imdb.com/list/ls098792662/
There is no reason for them not to shoot everything at 8K.
Look, 20 years ago when we were still using 4:3 CRT TVs, all movies, music videos, etc. were shot at 16:9. Why?
Theatrical presentation. It's not a surprise that 16:9 was selected as the compromise aspect ratio for HD. At 1.798:1 it's very close to the standard widescreen film aspect ratio of 1.85:1. On a 1920x1080p FHD display, 1.85:1 content needs fairly minimal letterboxing, about 21 pixels top and bottom.
And a lot of the production choices for content like music videos were forward thinking anyhow. 16:9 was part of the ATSC standard set by the FCC (USA) in 1996 so everyone knew that those TV sets were coming, even if most people didn't have them yet.
Perhaps more importantly, capturing at higher resolutions gives the content creator more freedom during the editing process. When you shoot at 8K with intent to release at 4K, you can choose which pixels to include. Filmmakers have been doing this for decades. For sure, Jim Cameron isn't shooting at 8K, selecting "Scale 50%" and pressing the Export button.
And it's not just resolution. Bits per pixel, colorspace, frames per second, etc.
The music industry has been doing the same thing, capturing at much higher resolutions than the planned output. So 192kHz, 24-bit full digital recordings have been happening for decades even if Joe Consumer is now listening over lossy Bluetooth with a pair of no-name wireless earbuds. And today there are even high resolution recordings (384kHz, 32-bit) using all the latest microphones, etc.
Same here and now. Shot at 8K, 16K or whatever special resolution they like, but publicly lying and releasing almost everything at 1080p or some at 4K...
Remember that 4:3 is a holdover from the old Academy aperture standard set by AMPAS in the early 1930s. CRTs weren't commercially feasible as widescreen displays (image accuracy, display weight, manufacturing difficulty, calibration, etc.).
A lot of content is being shot at much higher resolutions than currently available consumer sets can support. Again, this is forward thinking. It's just released as 1080p or 2160p content because that's what Joe Consumer's display can support and the bandwidth requirements for 8K or higher resolution digital distribution don't make it worthwhile.
But for sure, 8K and higher resolutions will hit movie theater screens before Joe Consumer's living room.
Let's not forget that 8K displays aren't just consumer devices. They are used a lot already in enterprise/commercial/military/educational sectors. There are art museums doing high-resolution scans of masterpieces (like Rembrandt's
The Night Watch) to be studied by academics on high resolution displays.
It's not just about a FIFA match, an Excel spreadsheet, or the next GTA release. There are plenty of non-consumer 8K usage cases already around.
Sony was ready five years ago to impress people with 8K video displays but COVID-19 scuttled that by delaying the 2020 Tokyo Olympics by a year (and no outside visitors were allowed in 2021).