Of course it completely ignores the main problem of any program code in the browser...
... that it's a gigantic security nightmare. Even if your sandbox is somehow "secure" it still can be used to suck your battery empty or mine $crypocurrency without your consent.
Then again the need for a platform independent "bytecode" for programs might have existed in the 1990s, but today we have moved on to distributing software in source form. Why turn back the time to where software was distributed in opaque binary files you had to disassemble in order to adapt to your needs?
Biting the hand that feeds IT
