As the author of this—yep, I can agree with that. I'm generally baffled when I see folks complain about Electron's slowness—but that's probably 'cause I started out building Swing apps :)
Memory usage is often a bad indicator of bloat. Especially GC languages like Java and JS will just go ahead and allocate a lot of memory from the OS without using all of it all the time. If you sum the "used" memory of all apps, it will often be more than the available RAM, even though there is no swapping going on. The OS memory management is really clever nowadays.
Actually, an app not using much memory may be sacrificing performance by not using a caching opportunity.
Unfortunately, apps coordinating how much memory to best use is an unsolved problem, as far as I know.
Is it really the case ? I would expect the language to expand the size of the heap only if after a GC the amount of free memory is still below a certain threshold.