Use Cases and Deployment Scope
So we use the YubiKey for securing most of our cloud services, like Office 365, Microsoft 365 mainly, but also other things like password managers. And as far as the services will let us, we try to use mainly the Yubikeys for the physical security tokens and trying to use them for passwordless access to avoid the risks of password theft.
Other Software Used
Google Authenticator, Microsoft Entra ID