Deno took a step in a good direction, but it was an opportunity to go much further and meaningfully address the problem, so I was a bit disappointed that it just controlled restrictions at the process level.
That is simply not true. There are many ways to do that, which have been answered already. SELinux. Seccommp profiles. AppArmor. Linux containers (whether that be OCI, bubblewrap, snap, app images, or systemd-run). Pledge and jails.
These are different concerns. One is software developers wanting to code into their programs upper limits to what imported dependencies can do. That is poorly supported and mostly not possible outside of research systems. The other is end users and system administrators setting limits on what resources running processes can access and what system calls they can make. That is widely supported with hundreds of ways to do it and the main reasons it is perceived as complicated is because software usually assumes it can do anything, doesn't tell you what it needs, and trying to figure it out as an end user is an endless game of playing whack-a-mole with broken installs.
