You can work from any device that has a browser without installing anything locally. If you work on different machines you don't need to sync anything.
The article said that it wasn't intended to replace VS Code... it was more for quick edits or reviews, for example if you aren't on your main dev machine.
Yep that’s correct. We’re making the desktop clients remote-capable, and the providing the web editor as a “companion” experience. We want to enable devs to use the right tool for the right job.
It provides Microsoft with tighter piracy control over their IDE with a better way to charge more for virtually the same functionality under the *aaS umbrella.
Oh, did you mean benefits for those not invested in Microsoft?