I have been using the "trick" outlined in Tentative procedure to make Joplin Portable truly portable on Windows for several months now, and it seems to work fine even over several major updates of Joplin.
This suggests that a genuinely portable version of Joplin could be feasibly released, by storing the necessary data alongside the executable and program files.
This could also help to solve the problem mentioned in Joplin Portable: Security Risk?