It means a lot of extra space. You are duplicating installations of Chrome and Node for each Electron app that is installed, instead of having one install and each app using the common dependency.
So yes, the developer gets complete control over which version of Chrome and Node is used, but you end up with a 150 MB text editor, a 150 MB chat app, and a 150 MB music streaming app, when you could probably get all three done with 152 MB using common dependencies.
Is storage space really that big of a concern, with many multiple terabyte drives being commonplace? Out of all of the issues with electron, I don't think wasting 150MB is one of them.
I think it worked pretty well for NPM where there was the high possibility of duplication between the modules you depend on and the additional modules required by them.
So yes, the developer gets complete control over which version of Chrome and Node is used, but you end up with a 150 MB text editor, a 150 MB chat app, and a 150 MB music streaming app, when you could probably get all three done with 152 MB using common dependencies.