1.) Carried out, that logic suggests not performing any outbound filtering because LAN hosts could simply find another way, protocol or port, out? I understand that 99.9% of LANs are configured default-allow LAN outbound. But the premise of your statement is untrue if the firewall is configured default-deny in all directions on all interfaces.
2.) I've not suggested 'blanket blocks' (nor 'blanket allows' for that matter). Specifically, both ingress and egress ICMP should be filtered by type code.
3.) In a zero trust model[1], every LAN device is untrusted. One should perform as much isolation and filtering as possible at all the relevant network layers. Network security is "disruptive" by definition.
4.) The second paragraph of my comment suggested that ping should be explicitly allowed for anyone/any device on the LAN legitimately utilizing it.