They set up online accounts by default to improve usability

Hahahahaha, you're kidding, right? Or do you genuinely believe this?

Unless you mean usability for MS tracking and telemetry of home users who lack the expertise of enterprise IT (which uses Windows Pro, and disables/blocks the MS tracking via Group Policy, which isn't available on Windows Home).

The reason for defaulting to an MS account, and making it practically required (they even hide creating a local account during setup if it has a network connection), is to capture even more user data and telemetry.

Now, defaulting to encryption is a good thing. But, the way to do it is to explain during setup (and have a process for) saving the key to another device immediately after setup - such as a thumb drive. Or even printing it, saving it to a text file, etc, etc.

It should also explain how critical it is, and not to trust saving it to a single device/location.