Make sure the game uses your actual GPU and not the integrated one.

Use lutris or bottles to set up and install battle.net automatically, from there install the game as you would under windows. Works just fine for me.

I've played WoW on Linux for twenty years. Blizzard has always said they unofficially support Linux. Occasionally the Blizzard launcher will have an issue, but Blizzard fixes it right away. All that to say, you should 100% have high expectation for WoW on Linux.

I use bottles to run Blizzard games with the latest Soda runtime. But as others mentioned, it's probably the integrated gpu that's getting selected. If you didn't use the automatic installer, (Lutris, bottles, etc., all have auto installers) for the blizzard launcher I'd suggest going back to that. But likely it's just the gpu selection.