The Flatpak issue is specifically because of distributions technicalities related to the proprietary driver. On AMD or Intel this isn’t a problem at all, in fact the block based update mechanism is much more efficient than most distro updates. It’s rather annoying, ur I believe it’s being worked on by the Flatpak devs.
Manjaro chooses to keep software back for a while, so multiple weeks of major updates all come at once. Add to that CUDA, the Nvidia Docker container, and LaTeX, and you easily get multiple gigabytes per update. It’s not really a problem in the age of terabyte SSDs and gigabit internet, even if it does feel quite pointless.
I’ve never really had many issues with Electron on Arch based distros. Arch packages most Electron applications as the required bits for a single Electron package that gets updated individually. On all other distros, Electron does waste a lot of space, though.