VSCode is like Chrome: based on opensource code -- not opensource in its entirety.
Even if one feels that way, in what way does that matter or serve as an advantage?
Atom doesn't have a corporation trying to slowly and quietly strangle the open source python language server to gain market share for their proprietary one.
Atom and VS Code are literally owned by the same corporation, though, since Microsoft bought GitHub.
The difference is that Atom is spun down by the owner, so this fork doesn't compete against the corp's version.