Remember vs code is designed to fracture and the forks are an integral part of that. https://ghuntley.com/fracture/
Maybe Microsoft should've made VSCode source-available. Sure, companies taking Microsoft's free labour would need to develop an IDE of their own (or maybe someone can hack Eclipse to work as a browser project?), but at least Microsoft wouldn't take the heat for not doing enough free work for everyone else.
You're massively misunderstanding the goals of these large companies who provide open source projects, whether it's VSCode, Android, Chrome, or whatever. The goal is always control. Companies at this scale never do free work for the common good.
I don't say this to deride them, I say it as a statement of fact that we all need to be aware of when we choose to use these products.
Anyway. OpenVSX is classic XKCD https://xkcd.com/2347/ territory—run by a small crew of brilliant volunteers, but the entire world depends/freeloads upon them.
Not sure if this outage and its long duration is due to some technical difficulty or an indication of something worse.