Not putting your WiFi password in would absolutely be reliable.

No, it would not.

I’d love to hear your ideas on how they’d remotely break into your WiFi Network

They wouldn’t, of course.

However, your network is not the only network in the world, and WiFi is not the only transport in the world. Neighbors exists. Open guest networks exist. Drive-by and fly-by networks exist. Mesh networks exist. Bluetooth, LoRa, cellular, etc. etc. etc. Maybe you live on an isolated mountain top where these things are unlikely to reach you (at least until satellite network links become smaller and cheaper), but even that is not absolute, and most of us don’t.

Unless you disassemble your TV and examine all the components within, and know what they do, it could have any of these capabilities. Given how prevalent multi-network support is becoming in electronics integration, it is not unusual at all for hardware functionality to be dormant at first but available for activation later.

I’d love for you not to be adversarial.