Ledger Blue has a built-in Bluetooth which was supposed to be used by some apps. Yet, users are not even able to pair the mobile Ledger Live app with it; they have to use a USB cable. As far as I remember, Ledger employees mentioned that it might also allow users to interact with their wallet without having to use a computer. Right now, there is nothing you can do with that large screen. Oh, and it doesn't support as many coins as Nano X and Nano S do.
Don't get me wrong, I don't hate Ledger. They released a product which turned out to be a failure, charged a premium price and didn't release many software updates for it (at least they tried to do something).