I'm familiar, and I said nothing about any of that other than that I understood the frustration.

That's also not the situation of the person I replied to. They thought the correct way to sub for someone in a meeting was to share credentials and log in as the other person.

I was calling out that absymally bad idea, and providing a work around.

To your point, you also shouldn't be mixing use cases of your devices. You don't want to end up in some legal shit, or in a data exfiltration investigation.

My personal desktop (and personal laptop when I still used one besides my work one) was a local account, signed into my personal Microsoft account via the browser. That could also work directly signed into the personal account instead of using a local account.

All work stuff stays on work provided hardware, or on a VM. I even spin up a light VM to just open a VPN session so I can remote into work resources. If I had multiple gigs, I'd make separate VMs for them. Personal Microsoft account never fucking touches these.

For elevated access accounts for work: separate browser, separate browser profile, or private browsing mode. Most admin work in Entra is through web portals (or Powershell).

I still can end up with minor issues from stuff like needing to use my admin Entra/Azure account to log into the Microsoft Graph Powershell module, so I end up with two entries in the Entra logon page on the work devices sometimes, but I just select the correct account if I get prompted. If it doesn't, logout of that specific system/program and select the correct account (which I'm logged into the work machine as). Loss of a few seconds, not this massive issue.