Comment by torginus

The problem with OS level sandboxes, and the reason why WebAssembly's being explored in this space (and Electron is so popular), is that relying on OS/hardware features means your TAM shrinks to a fraction of total, and it's historically well known you set yourself up to lose.

History is littered with tons of super cool OS features that didn't manage to gather enough market share and ended up as cool futures, and fodder for 'we invented the future 20 years ago' style articles.