I would almost say you can create anything with Mendix, but at some things it will take you more effort to build. Mendix is not a content management system. But since this forum has also bean made in Mendix it gives you an example on what you can achieve.
Where Mendix is extremly good at is to quickly build idears you have and test them out. You can build quickly. But if you already have a specific idear and the requirements do not change a lot you might be better off building in a traditional way.
Hope this helps you a bit.