Have you tried to remove (or rename) any existing .vscode-oss folder holding the installed extensions?
Broken for me too, I even tried deleting the .config folder.
Bug was filed on github/vscodium. Thanks all!
Visual Studio Code now supports ARM 32 and 64-bit, so we don't need these custom builds any more. Well, if you care about the telemetry you would but not me personally.
The reason I switched to the official build is that the extension store has Microsoft's extensions available.
I was really surprised how well it was working, even the C/C++ extension is fully wokring in Manjaro ARM!
I'm a web developer who usually relies on VSCode as well, so I completely understand your pain here. I've been trying to use this as an opportunity to finally force myself to learn NeoVim (or vim). I'm not jumping in with BOTH feet yet, but I'm getting there. My goal is to make my PBP a super light weight and minimal dev machine.
So I actually installed a bare Manjaro CLI and installed Sway and only what I need. The result is a quick PBP, but some learning for sure. The trackpad on this thing is ROUGH, so my thinking is, the more I get used to keyboard driven editing and navigation the better.. lessons I hope to bring into all my computers.
Good luck, and I might do a post about my NeoVim dev setup at some point.