This means you can't pass the game around to your friends or sell it afterwards, which completely ruins the purpose of physical media imo. I mostly play PC these days so this doesn't affect me, but it's a disappointing direction for console games. At least they could've used an empty disc that has proof of ownership.
EDIT: Bethesda has confirmed that only the PC version won't include a disc. Physical versions of Xbox will include a disc. Whew.
What's the purpose of a physical version if there is no disk included? This is nonsense!
They are trying to appeal to collectors but also want to squash selling or trading your game. MS has been trying to do this for 10 years.
From the business side Pretty much just being able to give it as a gift. Also make it more discoverable to people who aren't able to buy it online for whatever reason.
From the personal side No damn idea
To make useless plastic cases to help the environment, of course.