1. It's much more expensive that using a memory-safe language in the first place (maybe cheaper it if you have a big codebase already, but still very expensive

1. It's much more expensive that using a memory-safe language in the first place (maybe cheaper it if you have a big codebase already, but still very expensive and not worth it at all for new code) 2. Sandbox escapes are commonplace, and not everything can even be sandboxed at all.