inetd began to fall out of favour in the mid-late 90s as services became more heavyweight and startup times became longer (think of the initial crypto setup needed by sshd vs rsh/telnetd)

CPU speeds have increased & and i/o latency has decreased so much since then that startup times are generally imperceptible, so the pendulum has swung back to favouring socket activation.

The anti-systemd "traditionalists" never seem to acknowledge that history, though!