It seems there are hundreds if not hundreds of thousands of people who cannot sync their iCloud data with Outlook. I just ran across this and spent 5 hours 20 minutes finding the correct solution for my client.
Here is the issue, icloud contacts and calendar and tasks are not syncing with Outlook. There are several error possibilities or in our case there were no errors, just no syncing.
In this case we had Windows 10 Professional x64 and Office Home and Business 2019 x64. The end user uses an iPhone and iCloud photos et al.
Searching the internet it seems the troubled systems are Windows 9 and 10, Office 2013, 2016, 2019 and 365.