I don't know if it's only me, but did this guy... Did this guy make a huge mistake?
I think he was trying to bend reality with words. I can see many apps that are running in electron on my laptop, each consuming 300MB+ (e.g. Spotify), while many other apps are written in native Swift for example, especially with the help of AI, giving the best performance possible...
Edit.
And prices of RAM nowadays...
Those apps are not consuming 300MB of RAM because they are written in JS. JS is running on microcontrollers and the James Webb Space Telescope.
They are consuming 300MB of RAM because they are built on Electron and the NPM ecosystem.