I am not sure what clockwise is doing, but since calendar was mentionned, basically you need to break into M365, and for most entreprises, why acquiring another tool to manage calendars.

I happened to work for such companies, and the "application owner", and I am really not convinced by the ROI.

The real reason, VIPs didn't want to bother with a computer to manage their calendar, and they (well their assistants) had to organize meetings with 3rd parties.