It’s not because of electron. They could have multiple windows but it would be a massive over haul of the architecture . So they say just use another instance

I would argue that it is, because Electron doesn't allow you to share a js context across windows. So while it is not impossible, it is much more involved than it would be in most other frameworks. In fact, this is my only gripe with Electron where I think the normal HN objections about performance, bloat and lack of native UI elements are overstated and not something that bothers me.

That's basically the whole reason I'm sticking with PyCharm these days. Apart from that VSCode seems to tick all my boxes, but it's a deal-breaker for me. There's some kludgey workaround possible involving workspaces but it's rubbish.