Indesign Online collaborating Sharing options

As far as I know (and I'm not an avid Illustrator user) - the Share to Collobarate in Illustrator etc will invite others to edit cloud documents - but only 1 person at a time can edit the document - if you try and open it when someone else has it opens you'll be offered to  make a copy to your desktop.

So the whole thing is about making the document available for all to edit - but only 1 at a time - you can't edit it 'at the same time'. 

InDesign has Cloud Documents too - but work with a share to Review.

https://helpx.adobe.com/ie/indesign/using/share-and-collaborate.html

But nothing stopping you putting the InDesign file in the Cloud Documents and letting others edit it.

Or putting it on Dropbox/One Drive other File Hosting - or a Virtual Server somewhere... 

I've not heard anything about a feature to allow people to share an InDesign file.

Personally I don't think it's a good idea for multiple editors of an InDesign file.
Everyone works differently and approaches issues with different frames of thought, which can lead to inconsistent edits. 

In my opinion, I feel, it's best there's 1 key person who implements all the edits so the changes are consistent.

I think Illustrator and Photoshop etc. are a bit different, you're looking at maybe 1 or 2 Artboards/Canvas etc. 

But with InDesign you could have 1 - 3000+ pages to deal with.