This is also similar to how root used to work on Android devices. Since SElinux policies were enforced preventing the su binary from becoming root through setuid/setgid, a daemon used to start up at boot, and the su command was simply a proxy that connected to the daemon whenever called by an app.

However I wouldn’t call for the deprecation of setuid entirely: ping and traceroute still use them to set up raw sockets to send out IP data grams with custom values.