I guess you never heard of Outlook Calendar. It worked very well in the last company I worked in. And that was an IT department with over a thousand people. Busy people who needed to coordinate loads of meetings. So I have no idea where you get it from that our calendars don’t work well. AI is not an excuse to not learn basic principles of time-management or not to learn about the tools you are using. AI should help us solve problems we genuinely can’t solve with reasonable effort without it. Scheduling is one of the most trivial problems in all of informatics. Using AI to solve it is a complete waste of time and resources.
What I’m saying is: Learn to use your calendar tools in depth and you will probably find they do in fact work sufficiently well.