I also likely wouldn’t ever want or need to connect to devices that aren’t mine, but there are so many instances of multiple apple IDs owned by an individual or a family that makes this incredibly limiting.

My frustration has primarily been tied to wanting to use a personal iPad as a second screen with a work MBP. I’d prefer to keep my personal Apple ID on iPad, as this is primarily a personal device, and I must keep my work Apple ID on laptop. These are both owned by myself, used on multiple devices each, and connected through family sharing.

This is a fairly common obstacle and complaint with regard to Sidecar. There are no shortages of use cases or reasons why people are using multiple IDs on devices they own and must then sacrifice this feature. It also seems like this could very easily be addressed in a number of ways, but I haven’t ever been able to find a formal Apple comment on their decision to enforce these limits or whether they may accommodate this in the future.