@kota1 ,
For an 85" TV, the recommended THX viewing distance is 9.5 feet. For an 8K set, you need to be about 3 feet away to get the full advantage of the resolution. For a 4K set, you need to be about 5 feet. HD, about 11 feet. A 4K set makes sense to get the best resolution at realistic viewing distances. 8K for home really does not make sense.
It looks like 8K LED\LCD in Europe may be dead in the starting blocks at least in European sized sets. They won't pass efficiency requirements due to the high light loss from the reduced aperture. Don't remember, but expect at 85" you should still have a big aperture if everything scales, but maybe there are some limitations. The 8K, 85" SONY uses 50% more power than the 4K.