Agree if your computer resources are being utilized over 70 percent teams becomes a nightmare. They could have written it in c++ in the same amount of time and had that thing running smoothly.
Well it's a lot easier to make an app perform well in C++ than electron.
They should at least have for the VS Code team to help. That's one of the best performing Electron apps, it's strange MS never adopted those practices company wide.
Either way, even if this was the reason it would prove that Electron is not a good fit for an app like this.