The very much ‘partial’ implementation of calendaring/calendar integration (and also video conferencing integration) is a definite pain point for Enterprise use of Discourse.
When trying to get inherently Microsoft-centric workplaces to adopt Discourse more deeply, it can be frankly embarrassing to have to admit at the end of a topic entirely conducted in Discourse, which might have even included neat features like a Discourse poll for the date/time, that we then have to drop a Teams/Outlook link for the calendaring bit. Most teams are not (especially initially) willing to fully adopt an in-Discourse calendar, which requires extreme Discourse buy-in from the participants.