If commit activity graphs are really a meaningful measure, look at VSCode's:
https://github.com/microsoft/vscode/graphs/commit-activity
The number of commits per, uh, date unit (the graph is not super clear on that axis, honestly) across the entire length of VSCode's activity graph rarely drops as low as the highest number of commits per date unit for Atom.
I'd have preferred to see both survive and do well, but that really hasn't been the way the text editor space seems to have worked. Editors that are conceptually awfully similar to one another tend to have one dominant player: TextMate (at least for Macs), then Sublime Text, then Atom, then very quickly Code. Given that Code and Atom are probably the closest of any two in that list, this just isn't that surprising.