A tab on a browser the user is already running would cost less memory and CPU.
It's also with chrome super easy to open a page without the normal browser UI that looks like an app add a .desktop file and presto it's an app it would actually be superior in many respects.
Electron is like its own possibly out of data copy of chromium packaged with other resources.
This means that it shares little with the installed browser and will consume 300MB-1GB of ram itself.
I do not suggest a web app is an adequate replacement for a native application but rather that a website may be a superior alternative to electron as it uses fewer resources while providing a similar UI for some applications.
It's also with chrome super easy to open a page without the normal browser UI that looks like an app add a .desktop file and presto it's an app it would actually be superior in many respects.