Not every network requires a password.

Encrypted ones do, at least every commercial version these TV’s would be able to use. https://en.m.wikipedia.org/wiki/Wi-Fi_Protected_Setup Is the closest thing to an exception that I know of but still required user action to connect, and it’s been deprecated for a long time.

Some enterprise systems don’t require users to enter passwords, but the software still uses them internally when talking to the network.

PS: Unless you know of some other exception?

Nothing’s stopping TVs from hopping on unencrypted networks.

WiFi has limited range, so some people have control over what local networks exist.

Or even from silently bruteforcing passwords.