This.

An appliance should turn on when I turn it on, turn off when I turn it off, do the task I instruct it to when I instruct it to, and do nothing that I do not instruct it to. Its status should be clearly indicated to the user with a few LEDs, or a numerical display if needed. Its behavior should be entirely predictable at all times, until eventual mechanical failure due to wear.

If an appliance design fails any of these checks, it is a bad design.

If any function of the appliance is dependent on a network connection, it fails the checks because:

• it will do things that I did not instruct it to
• it might fail to do things that I instruct it to
• it might not fully turn off even though I've pushed the power button
• it might not fully turn on if it can't find a network connection
• its status may be shown on a garbage-quality failure-prone LCD, in a UI designed by a CS intern with 3 months of classroom experience in Java (or worse, an LLM)
• it may behave unpredictably due to bad software design by said intern, and will typically be exposed by poorly designed network security, leading to behaviors controlled by malicious third parties
• it will fail early, if not because of the shoddy bottom-of-the-barrel electronics, then because the manufacturer decided they weren't going to support the companion app anymore (6 months post-purchase) so fuck you, buy our new product that doesn't actually have a complete companion app yet! (the intern is still working on it)

Don't buy "smart" appliances. Ever.