Being isolated is good and bad for WASM.
You get lots of benefits, but then you cannot use any C system calls which most code relies on (networking, disk, GUI) etc.
It looks like runtimes are going to create message passing interfaces to access these C system calls.
Wouldn't it be easier just to create better sandboxes for the old code rather than create a WASM runtime with new message passing interfaces to all the old C system functions?