If you're writing server stuff, at the coarse-grained level of isolation that Deno provides you're better off using just about anything else and restricting access to network/disks/etc through systemd. Unlike Deno, it can restrict access to specific filesystem paths and network addresses (whitelist/blacklist, your choice), and you're not locked into using just Deno and not forced to write JS/TS.
See `man systemd.exec`, `systemd-analyze security`, https://wiki.archlinux.org/title/Systemd/Sandboxing