I couldn't disagree more. Phones UIs tend to be pretty terrible (the good ones just rise to "not terrible"), and I certainly don't want the various devices I use to have one. That's why I will not buy devices that require it.
The limited hardware almost guarantees a poor experience, and of course no consistency whatsoever across appliances.
Sure, 3 buttons is ok just to set the time perhaps, but quickly becomes unusable with more complex requirements - and then you get crappy lcd screens, and custom menu systems, etc. even bad apps are usually better.
I'm generalising to more complex appliances, but no, just adding buttons doesn't do it (quite apart from more points of failure), even for a clock - how would you set multiple alarms, say one for you, one for your partner, with different times each day of the week. do you have 2 buttons for each day, or what? Of course, in reality you end up with modes, and menus , and a crappy custom UI.
Multiply this by every gadget in the house, and a full UI remote (be it phone, tablet or specialised wireless touch-screen remote) becomes an attractive option.
The connected can be controlled by apps or heck, APIs, perhaps offers full flexibility etc. However, what guarantees the controlling app is going to keep being updated? What if there's a wi-fi vulnerability in a few years? What if there are calls to company servers that go offline? What if you phone is off and you want to quickly set the time?
The unconnected can be controlled by a physical unchanging interface. It offers few extra features, its buttons will wear and break, etc. But it probably will function just fine in 10 years time, is probably extremely easy -- and less time consuming in total to set. I disagree the experience will be poor or inconsistent -- those products usually obey a common language of household appliances that works well enough. Physical buttons are usually very responsive and easy to use. There is not much to go wrong.
The ultimate measures here are probably net productivity (time wasted on clock and setting time), cognitive load, and robustness. If you have specific timing requirements maybe the networked clock is for you, but for most people I'd say the good old digital clock is probably still easily best.
Maybe in the future the digital infrastructure will be standardized and simplified enough that more appliances will become connected, but the real value of 'iot-enabling' is still quite low for most objects.
Remember, newer or more flexible isn't necessarily better (even for very complex systems: see UNIX philosophy).
Well, it depends on the appliance. Some really are terrible. But on the whole, I think appliance controls tend to be more usable than smartphone interfaces.