A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
A passkey is not being forcibly setup. What's happening is that you are being asked (others might say 'pestered') to setup a passkey, every time you log in to your Microsoft account. This is not limited to Microsoft. You will encounter this at every website you visit that has passkeys implemented. You cannot prevent being asked/pestered, not by Microsoft or any other website.
There is no 'official' explanation for this, other than what you have read about passkeys being safer.
In my personal opinion, if a passkey was only about you and me, we could stop it. But it's not only about you and me. Every data breach exposes the organization to unwanted scrutiny and legal action. A passkey cannot be stolen, even if an organization is breached (which is not going to end.)