COD Black Ops 6 - Why do I need to buy the next/cross gen version even though I’ve already...

From what I can tell, to access the Series X version of the game, you need the Cross-Gen bundle...once you buy that, you should then be able to download and install the Series X version. Without the cross-gen bundle it will, presumably, just install the XB1 version

From the Store page:

"For digital owners of the Call of Duty®: Black Ops Cold War Standard Edition, this upgrade will unlock the Call of Duty®: Black Ops Cold War Cross-Gen Bundle, giving access to the Xbox Series X|S version of the game. After upgrade purchase, search in the Xbox store for the Call of Duty®: Black Ops Cold War - Cross-Gen Bundle to install the Xbox Series X|S version of the game."

It shows I own the game and even though I own the cross gen I’ve bought the cross gen upgrade to but it still asks me to purchase it .

Not until the next gen versions will we know. The current gen version of BF 4 doesn't hold a candle to even Black Ops 2 (which is unfortunate).

I have the exact same problem pretty sure I paid extra for the cross gen version a while ago. But I upgraded for $10 bucks even after that I still have no ray tracing or hd assets. I’m so dumb I bought the whole cross gen version again for $48 on sale even though the store said I already owned it. I’m trying to get a refund now for buying the same game twice

Yes. If you buy the cross-gen bundle, you'll get the Xbox One version and the Series S/X version. Even without the next-gen upgrade, you'll be able to play the game via backwards compatibility.