The demand is 100% there. I asked the NC engineers about Sorts at the conference and what I was told is it is extremely awesome, but would have benefited from input from the team in order to be developed with even deeper integration to the Files app. As is, needs a full rewrite afaik.
Also, sounds like it would have been top app at the conference if it had been submitted.
Dear programmers, can you add this:
Nextcloud should have a setting in Calendar to display ISO 8601 date/time standard presentation.
It’s hard to believe Calendar was created without this setting.
“Move to Folder” functionality ala Google Drive.
Change where something is stored on the filesystem without leaving the current application view.
Makes it easy to keep whatever item you are accessing organized in a location you prefer.
On the Calendar have a Long List option.
Scenario: We’re trialing using a shared calendar to plan events for a youth group, so we’re looking approx 6 months ahead and sometimes get save-the-date info for district and county events upto a year ahead.
The List option just shows the events for the current month, they’d love to see the full list of what’s being thought about all on one page.
Being able to scroll back into the past would be useful too, so maybe a list with a from: to: range selection would give more flexibility. Some of the kids activities are takes a few sessions for them to complete during a term so being able to see what was on the calendar in the last few months before as well can be useful.
One great missing app is NextCloud Sites!
Something like Google sites but I’m sure it’ll be much better. The simplicity and ease of use of Google sites is nice but it lacs some essential and new feature for quite some time.
On the other hand, with NextCloud you have user control and would make such site perfect for intranet and document and announcements place for you company.
Integration with files and flows will be even greater. And hosting would already be present so you would use a subdomain.
This was excactly what the picoCMS app added. You can have something close to this with collectives, however I agree, fully, that it is not enough. If only the developers of the PicoCMS app was active. 
Nextcloud Calendar should have a “planning view” as Outlook has. This is basically the view that you currently have wenn having added participants and are looking for free/busy times.
This might already exist, see the tip at Using the Calendar app — Nextcloud latest User Manual latest documentation
I miss the feature to share single calendar itemswith several calendars/users.
I have cases where I have webcals with some dates I wish to share among our family. The updates that arrive on the webcal should also update the calendar item of all shares.
I miss a template creator for print and a basic template creator for Online Office.
What should it contain:
Wherever I do a Print from Browser The Nextcloud Content is prepared along this. May add a Printer Icon that create a PDF for downloading.
If no template is chosen Online Office used these settings for new documents.
There are tools for work time in Nextcloud. May they could be enhanced.
Currently, a Friend of min is working as a Head of a Team in a corner shop. He use pen and paper to place his people into shifts. It’s getting harder and harder because his people mostly only work part-times and has to be sure that the shop permanently has enough employee and also a certified person for their apprentice ( Vocational education) on times the apprentice is not at school.
So he needs a tool that auto generate shift scheduling at least three months into the future.
That allows to see problems far enough.
Idea is.
Currently, he struggles again like every year with the intense xmas time.
I would suggest support for Caldav subscription - that is add a CalDav based calendar into my feed.
If there were good management of multiple calendars that would go some way, but once you’re matching skills and contracted hours, you’re really getting towards full-blown ERP.