>Atom doesn't use 80MB, it uses 800MB.
This is an over exaggeration, and quite a large one. Facebook just released information on the average memory usage of "nuclide" (their Atom editor bundled with a metric ton of plugins which use quite a lot of memory) to be around 600mb. And that's not indicative of a "normal" Atom user (if there can be such a thing).
I personally have currently 5 windows open in atom, with about a combined 40 tabs, and about 30 plugins installed, and my instance is using 360mb of memory right now across all processes. And those windows have been open for about a week now.
And that Atom instance is running a lot of what your Eclipse instance is running. Linters, autocomplete, code analysis tools, CI server integration, a webserver for serving up my application in the editor, a debugger that links the live preview in the editor with the code in the editor, and a ton more.
Switching to something which uses a few hundred less MB of RAM for a fraction of the capability would be a monumentally stupid thing to do, as Atom makes me significantly more productive than any other editor I've tried has ever before.
There are a lot of problems with Electron, but memory usage isn't one of them any more. It can be, just like with any language/platform, but it's not "inherent" to the technology.