And from there you can use GitHub Codespace to "develop in a cloud-hosted, customizable environment" to run and debug.
To be clear, I'm talking about the VSCode app. Once you visit it they hijack the browser history and hitting back causes the entire app to reload, over and over again, until you manually drop down the history menu and jump 2+ pages back.
I realize now my comment sounded rude and pointed toward the parent (not at all the intent) - I can't edit it so here I am again.
The proposition here is that the IDE provides dev process tooling so you are in fact collaborating with your team, e.g. reviewing your code, but Github (Microsoft) and other centralized services are not necessary and not included in the activity. And yes, if AWS etc goes down, your IDEs will continue to work and you can continue to collaborate.
The terrible flaw, to me, sounds like it's the workflow that won't bother installing the right tools for code review. It's not like you're stuck with printouts or something where those tools aren't practical.
(If the IDEs or editors are lacking things needed for code review, then that's a problem, but it's not a problem inherent to the idea of tight integration.)