At first I thought the same but then I realized: smart appliances/tech only works when powered and we often forget (or visitors forget) and switch off the lights or other things at their physical power switches, rendering the smart stuff useless until physically switched on again.
These allow for that but with the ability to turn stuff on again with voice or other smart means.
But the price of these buttons is absurd. I’m tempted to get some Flic buttons with their new hub. If they’d confirm they’re adding HomeKit compatibility, I’d have already pre-ordered but they’re being sketchy about committing to that functionality.
Thanks for the Flic comment, although still not really cheap it's a better option then the buttons this article is about.