This feels like an attempt at deflecting blame. VSCode is another Electron application that ended up having better performance than Atom. There's another Electron adjacent application that has good performance, the one you're probably using right now to read this page.
Depending on page content of course
VSCode can pretend to be fast in my desktop, and I would not care because desktops today are computing monsters that rival supercomputers of the past, but Sublime Text is still much faster at any text editing task.
Atom was kinda like emacs. Extensions could do almost anything. VS Code has a limited api that extensions can use
Web technologies are an unrivaled technological marvel for what they are, but it is disingenuous to imply they represent anything near the peak of what we are capable of in the context of performance.
In my experience VSCode is plenty fast. Use it with no extensions and you will have zero problems with performance (though memory use isn't great). The real problems come when you have extensions, especially because it's often impossible to attribute performance issues to them because they can often do a lot of work all in the same "extension host" process.
Memory use is a part of performance, though, so I definitely would say VS Code has serious performance issues. It's why I no longer use it, in fact. It's inexcusable for something to eat as much RAM as VS Code does.