The button is faded out for me: https://download.battle.net/en-us/desktop

But as soon as I change my user agent suddenly it works 🤔 However starting it with wine gives an error that it can't connect to the server. No more blizzard games I guess

With a previously installed client I was able to buy and download Diablo II: Ressurected, but after starting it it immediately stated that my setup was to outdated to run this game. I highly doubt that, since I have more than the minimum requirements.

I found out that you have to fool the game to make it start: https://forums.lutris.net/t/solved-diablo-ii-resurrected-fails-to-start-with-failed-to-initialize-graphics-device-error/13878/3

Problem was with ingame GPU and driver version detection

The lutris battle.net installer however did not work, and I didn't have the mood to debug it.

Not so surprising, but they don't support linux: https://us.forums.blizzard.com/en/d2r/t/failed-to-initialize-graphics-device/5896/67

Note: Linux, bootcamp, or running the game in a virtual OS is not supported