It CAN get pretty wild sometimes, though. For example, Flameshot (screenshotting utility) is only ~560KB as a system package, while its flatpak version is ~1.4GB (almost 2.5k times as big)
Flameshot is 3.6MB on disk according to flatpak info org.flameshot.Flameshot
Weird, the software manager (using LM 21.3) reports 1.1GB dl, 2.4GB installed (which is different from when i checked yesterday for some reason?).
flatpak install
reports around 2.1GB of dependencies and the package itself at just 1.3MB
EDIT: nvm im stupid, the other reply explains the discrepancy