One of the biggest things I hate about Android’s Play Store is how the changelog on most apps has become useless, and many apps just put “Various improvements and bug fixes” for every update and just expect you to keep updating.
Flathub is similar in that most apps don’t have a changelog at all - it’s just blank. This hurts discovery of new features, satisfaction from bug fixes and enjoyment of enhancements. More should be done to help ensure apps have changelogs.
I’m not sure what the best approach to improving this is. There already is some documentation which points to 3rd-party docs, so maybe one or both these docs need improving.
For apps where the upstream doesn’t have a metainfo there perhaps needs to be a tool created to help extract changelogs from commonly used sources e.g. GitHub releases page for open-source apps, text files formatted as changelogs, webpages, etc. Whatever the solution(s) are I think at least getting full coverage for the open-source apps should be a goal.