An empty Atom window containing 5 source code files consumes about 120MB of RAM. For comparison with native apps, an empty iTerm2 window uses 100MB, and so does an empty Notes.app window. The base memory footprint imposed by Chromium is not that significant.
Granted, it is totally normal to have packages when using Atom, but their memory cost shouldn't be considered a penalty that you pay due to Electron. Rather, it's a penalty that you pay if you want an extensible application in which extensions are allowed to use JavaScript.
When I run `atom --safe` it starts at around the same amount of memory usage: https://imgur.com/j4Co4n6.png
Side note: Running that command is now preventing my from quitting Atom using the Atom > Quit menu entry. I had to force quit it to get it to close.