Org mode can display images inline. They’re obviously not stored on the file itself, but I keep everything under a single directory hierarchy and it works ok for my use cases.

I migrated to org from Things some 12 years ago and since I started bare-bones (just todo entries, no special config) and grew as my needs arose, I never felt I had to invest lots of time in my setup.

Agree that some people overdo things and the tools become projects on their own though.