Unselecting Example Content during the creation of a new website in advanced mode does not install the default Plone content types (and there is no easy way to do it via Plone's UI).
I was expecting only the example content (Frontpage. news, events...) to be missing, not Dexterity and its plone.app.contenttypes.
This is quite an old issue, when Archetypes was still a thing
I think the checkbox should just create "Example content" and a default Plone 5.2 should come with it's content types configured. Probably just a restructuring of profiles/depencies is needed.