I’ve been using the custom email domain feature that comes with iCloud+ for some time now, and have had zero issues with it. I imagine many of us here already pay the measly 99¢ fee for additional storage, but I was unaware of that addition until recently. Awfully easy to do, even if you’re wary of DNS. https://support.apple.com/en-us/HT212514
Lack of catch all there seems to be a blocker for many including me
This is probably the best dollar I spend every month