Almost since its inception iCloud has evoked a Love/Hate response from users. Either you like it and embrace it an all its features or it is a complete anathema with few in the middle. Admittedly I am among former.
That said I was looking to see if there is anything new in Monterey, I might have missed and came across the mention of a new iCloud+ feature that wasn't even mentioned in the keynote —
custom Email DOMAINS. The ability to create multiple email domains that you can use on-line or in Mail on macOS, iOS, and iPadOS that can be used for sending and receiving email, text messages, or FaceTime calls. If your iCloud+ account is a family account, anyone in the family can use the same custom domain. It is in beta at this point and takes several steps to set up. I am just beginning to test it out, but if you are interested you can find full instructions
here.