Does the encryption keep the user's data safe if the device is lost or stolen? Yes? Then it fulfills its main purpose.

Not everyone does everything from a web browser.

And it's even more scary that MS uses dark patterns to trick older non-technical users into enabling MS online accounts. When the bitlocker activation automatically happens during tricking the user into going from a local account to online account it is without the user's consent or real participation. They don't print out a copy of the key or move it to a usb drive becuase they aren't aware their drives are being encrypted. And afterwards they can't set up recovery keys because the computer itself only shows the blue aka.ms screen. It's effectively dead until they follow the demands.

This is not theoretical, it actually happened to my mother on the local account Win 11 computer I set up for her sewing applications. I had to drive across town in order to figure it out since the weird URL I'd never heard of (aka.ms) and demand for pasting private info sounded so much like ransomware. And in fact, it was effectively ransomware, it was just demanding online activity rather than money.

Nobody deserves to be abused.