But that’s exactly what we do have! Any old router/AP combo you buy at the store or get from your ISP will let you set up a normal network and an isolated Guest network. All with a nice UI/UX that involves checking one box and choosing a password. Considering WPA3 to be insecure is just not rational or based in reality. Exploits against it are really complicated and just don’t happen all that much.
I don’t have to trust all the junk IOT devices that end up in my house because I just throw them on the guest network and call it a day. Nothing bad is going to happen to me as a result of this practice.