Essentially yes, if you start using lots if older applications or mixing applications that use many different dependency versions, you will start to use lots of extra disk space because the different apps have to use their own separate dependency trees and so forth.
This doesn’t mean it will be like 2x-3x the size as traditional packages, but from what I’ve seen, it could definitely be 10-20% larger on disk. Not a huge deal for most people, but if you have limited disk space for one reason or another, it could be a problem.
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
