If I had to guess, which currently I do as GP has not provided an answer, I would guess it has to do with the the ease with which the flatpak can be updated mal

If I had to guess, which currently I do as GP has not provided an answer, I would guess it has to do with the the ease with which the flatpak can be updated maliciously compared to a traditional OS package that usually goes through a separate maintainer. Thus, if the project was hacked or the owner of the flatpak turned evil, they could reap a pretty major bounty with no blocks in the way. If this were my concern, I would just build from source as it is quite easy to do with this project.