Whne you track appointments to Dynamics 365 using the App for Outlook, you are not able to pin the Outlook App pane on the RHS of the screen like you can when track emails. When in the calendar, you have to open an appointment, then open the app, then it authenticares. This all takes time.
Many companies have their employees track time into Dynamics and use it as a billing tool. This arduous way of tracking appointments makes it too time consuming.