Earlier quoted context omitted.
So, now we have a single certificate on all routers? What happens if I take apart a router? Or would every router get its own certificate? But then netgear would have to become its own CA. And in either case DNS hijacking is a massive issue.
Or would every router get its own certificate? But then netgear would have to become its own CA. Why? They could just partner with an existing CA, like Cloudflare does with Comodo. And how would DNS hijacking be an issue? The attacker wouldn't be able to produce a valid cert anyway (the router would come with a custom burned-in key that it would use to authenticate itself to the CA and get the cert).
I take apart the router, and get a valid certificate. Now I hijack DNS, and get you to connect to me.
HTTPS within LAN for this purpose is useless.