[blep_]

The JVM did that many years ago and nobody liked it. I can't help but think wasm is just the same idea but worse.

[yencabulator]

Outside of web applets, set-top boxes, and DVD players, JVM didn't really do much sandboxing. On the desktop or server, it did practically none.

[mdaniel]

I think the rest of your sentence was "by default" which is the same thing the comment you're replying to said: "security gets in the way of everything"

One could always launch any java process with java -Djava.security.manager -Djava.security.policy=someURL and it would sandbox a huge number of things (see: https://docs.oracle.com/en/java/javase/17/security/permissio... )

The problem is that defining a reasonable policy for any modern app is a gargantuan pain -- as is the case with any security policy language -- so as the GP said people hated it and now it's dead https://openjdk.org/jeps/411