Contentful (and similar services) also _can_ invest lots of time to get a good looking and super usable admin interface that can tackle difficult problems well.

Contentful (and similar services) also _can_ invest lots of time to get a good looking and super usable admin interface that can tackle difficult problems well. Examples: Sorting of ordered many to many relations, WYSIWYG or markdown editors, workflows, versioning, concurrent editing of items - all the stuff that you don't need for an MVP but if you have hundreds of editors and non dev people working on the actual content.