On my machine, an empty Atom instance is using about 400 MB: https://imgur.com/S1POSPz.jpg
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.