Administrators have full control of the content they accept and they decide whether sensitive content (violence, pornography etc.) is displayed by default or not. In its default configuration, PeerTube hides videos that contain sensitive content.
Therefore, you may find inappropriate videos on some PeerTube platforms. But it's far from being the majority of the PeerTube content. For example, in September 2021, the 900 platforms listed on our public index host only ~1% videos tagged as containing sensitive content.