Note that VS Code is built on Electron and it is a pain to sandbox because Electron has (had?) SUID sandbox helper, and you cannot run SUID binaries in sandbox easily. Sandboxing on Linux is extremely difficult task.
Don't build your ide on electron then.
podman seems to handle rootless namespaces just fine, minor caveat for some perf overhead but it's not the end of the world.
It feels so bad to see the "You need go give Chrome SUID Root for the sandbox to work". Setting a Web Browser SUID Root was an old joke about clueless users. It was the worst security screwup someone could imagine.