I had my home wifi configured like that for few years. AP without any security wired into network that was firewalled such that it only allowed ICMPv6 and OpenVPN. Sadly this worked ten years ago, but is completely unusable for various IoT-ish devices (for me, Wii was the device that made me to switch to WPA2-PSK)

Edit: also at that time this was at least subjectively significantly easier to setup than wpa_supplicant ;)