Surround formats change ... there will alway be that pull to get the latest ... and usually that means upgrading your receiver/prepro.
Chesseroo maybe able to sweat it out as the world around him moves on but I'd plan on a bit less time than a decade plus. Just MO.
I'm not sure 8k will ever be worth going for at home. You'd have to sit uncomfortable close to your 4k screen to want that resolution.
8k, IMO, is practical if your a video editor. Each process you put your edit through eats a bit of resolution.
