I have a 2080 Ti which I got used for much less than retail 4 months ago and Netflix app always plays 4K, you can check the resolution by pressing Ctrl + Shift + Alt + D. You need the HEVC codec from app store.
I will skip the 3080Ti as my OCed 2080Ti can run anything maxed at 4K60Hz which is the max of my monitor. Also it will be much more expensive vs 2080Ti because of no competition and lack of stock due to corona virus. I will upgrade in 5 years when I get a 4K120Hz OLED(?) monitor.
By much less do you mean $1100? I don’t think the 3080ti will be as expensive if AMD and Intel start eating at Nvidias main cash generator the low end gpus. The most popular graphics card is the Gtx 1050 and Gtx 1060. Nvidia sells way fewer 2080ti’s and the profit margins are much lower for the higher end cards. If you look at Nvidias financial statements their gaming revenue has drastically gone down, not including their data center revenue, especially because of their ridiculous prices. And with increased competition from the Xbox series X, PlayStation 5, and AMD Navi, I highly doubt they can continue to charge ridiculous prices.