We should avoid building new projects around TYPO3 by default. A lot of past projects started with CMS-only features in the beginning, and, for example, developed toward highly customized E-Commerce platforms. Instead of rearranging the architecture in a useful way, functionality was built on top of TYPO3's core and its extension framework Extbase. In the context of larger projects, this lead to deployment monoliths and the inability to integrate new technologies.
While in the past it was easy to kickstart a TYPO3 project with AOE's custom-tailored kickstarter, we now have a lot of knowledge and tools available to start projects with a much smarter architecture. This does not mean you shouldn't use TYPO3 anymore, but use it as the tool it is: a content management system.