As far as I understand, haptic technology requires your skin to touch the button to register a press. In other words, it won't work through clothing or gloves. Correct me if I'm wrong, but that sounds like a huge inconvenience since there is no more adjusting the volume without taking your phone out of your pocket. And those of us who live in colder climates better take those gloves off every single time we want to press any button on an iPhone.
And what about silent mode? Who needs visual feedback or an orange indicator to know which mode your phone is currently in? Spent an extra 5-10 seconds looking for your iPhone menus to see if it’s in silent mode or not.
I know Apple seem to argue that state buttons with haptic feedback further improve water resistance. The current water resistance is more than enough for 99% of regular iPhone users and those who need more can get a waterproof camera for their underwater adventures.
Also, haptics requires a battery to work, so what if the haptic engine fails? It will make using your phone even more fun, not knowing whether the button works or not when you are trying to restart it. So yeah, let's add more unnecessary features to replace perfectly working features that also drain the battery. What an excellent trade-off!
In all seriousness, this is a terrible idea. Physical buttons don't need batteries, and they're more reliable. Apple should focus on improving other aspects of their phones, like cold resistance, which would be much more appreciated these days. Apple should have learned that their improvements are not always great, and this concept has a touch bar and butterfly keyboard stink all around it.