My family bought a big Vizio TV around a year ago (IIRC), and I'm pretty sure we didn't have to sign in to anything for it to work. We didn't connect it to the internet. It often prompts for an update to the remote but the prompt goes away on its own if you don't do anything.

The model is V4K75X-0810 on firmware 86.710.52.1-4. The "Last Update" field says "Dec 31, 1969 04:00 PM" :D

The remote firmware is 6.02.1. I wonder if the reason it prompts for an update is because the TV has a newer remote firmware built-in or if it is just guessing that a newer update is available online.

I don't remember if we had to do anything weird to get the TV to set up without internet.

I agree regulation is probably needed.