Calendar invitations just don't work - email or in app

I've been troubleshooting this issue for more than a year using the suggestions in different threads. I can never get meetings/events added to my icloud calendar regardless of whether the icloud settings are set to "in app" or via email. In-App, the notifications never show up in the calendar inbox. For email, I get the email message, but there is never an opportunity to accept the invitation. I've tried downloading the attachment and I can honestly say that those extra efforts are just a waste of time.

How about we get Apple to remove ability to add events to the icloud calendar. It's time to quit wasting all our time. I'm an IT professional, and I can honestly say that nobody should need to make these adjustments for ability to accept/add calendar invitations via email and/or in-app to work.

Hate to say it, but Microsoft is working better. I'm using Outlook calendar and email for this stuff now. Two years, multiple devices, and it just doesn't work.