I find myself wondering just how complicated TVS could actually be before it’s no longer possible to hijack the display signal that’s fed to the display

Unlike with cars, TVS seem simple enough that a sufficiently motivated novice could modify a cheap TV to circumvent these bullshit features. If they ever started requiring internet connections to start or use these, i think enough people would be bothered by it that there would probably be a secondary market of modified hardware

As with most enshitifications, the question will ultimately be one of complacency of the average consumer.