/var/lib/flatpak/app/org.gnu.emacs/current/active/export/bin/org.gnu.emacs is not what I expect a Unix system to want me to type if I want to run Emacs. Nor is flatpak run org.gnu.emacs. These are tools built by someone whose mental model of running Unix software is “click the icon in the Gnome launcher”. That’s one aspect what I’m describing as not being “simple”. I don’t want my mental model of how to run Unix software to include “remember how you installed it and then also remember the arbitrary reverse-FQDN-ish string you need to use to tell flatpak to run it”. If I’m honest, that alone is sufficient to signal it wasn’t built for me. I could work around it for sure with shell aliases, but I could also just not use it, and that seems fine for me.