Every confluence installation (both cloud and on-prem) I've used in my past 4 companies has always showed a list of child pages if they existed, when viewing any given page.
Now that we've migrated to Confluence cloud version at my new company, this is no longer the case. Parent pages are easy of course since they show up right at the title. However, it takes several clicks and digging and scrolling to find child pages, which seems very unintuitive.