[ktsmith]

Most consumer routers use self signed certificates which will be marked as insecure by the browser.

[craftyguy]

All modern browsers allow you to import certs into their trust store.

[jononor]

But the UIs for that is actively discouraging people from doing so.

[aldanor]

Besides, I believe, the majority of people using router config page wouldn't even know for sure what 'importing certs into their browsers trust store' means or why it should be done and where those certs are etc. There's a ton of consumer-unfriendly terms and concepts, plus, as the parent noted, the UIs are usually discouraging.