What people call "real buttons" usually require a certain force and travel to activate. Capacitive buttons require little to no force or feedback, sometimes not even solid contact.
I think the easiest way to understand the difference is to ask 2 questions: "can I put my finger on that button and not immediately trigger it" and "can I can physically tell that I am triggering it (ideally some physical travel)?" If the answers are "yes", then it's probably the kind of button people look for when talking about wanting "real buttons".
Apple has actually combined the two with their touchpads. When you press on them you get the "click" feedback. But its not actually a physical travel that activates, it's what they call "the haptic engine" that vibrates in a way that makes it feel like you've clicked a physical button. It works really well.
However, I think that such buttons are far more expensive than a physically activated button, even if the latter is engineered to last a lifetime of heavy use.
> But its not actually a physical travel that activates
This was the little (to no) feedback of a press I was mentioning. Simulating the absolute bare minimum of travel. With the pressure sensors and the piezoelectric actuators it becomes a super-expensive, overengineered button simulator that works almost as well as the real thing.
Even Apple dropped the fancier 3D touch completely, and the less fancy Force touch is just for trackpads. Everything else is the cheaper Haptic touch doing away with pressure sensors entirely. It was fine for my iPhone 8 home button and old watch.
But a car is different. A hazard light button has ~5mm of travel. Blinker or wiper stalks have centimeters of travel. Same for rotary knobs. They're also well spaced from each other with hard to confuse actuation methods. In noisy and vibration prone environments, with time sensitive requirements, you want to have very clear and distinct ways to act and receive feedback that actions were performed, especially if critical for safety.
I do not disagree with you. I was pointing our that there is a certain class of physical buttons we can replace with an "emulation" that works just as well. That is not to say we should.
The parent commenter was making the point that the particular buttons on the latest Model 3 (Highland) actually feel almost like physical buttons. They require pressure and won’t activate just by being brushed against.
Still, as blinker controls they don’t have tactile markings and a stalk would be much better.
You're correct. But I was addressing GP's wording (emphasis mine):
> those 'haptic' buttons are real buttons
I was making the point that it's not a "real button" if, as you also say, it just "almost like" a real button. Knowing the M3 buttons, that "almost" is doing a lot of heavy lifting. Press a classic hazard lights button, and a Tesla signal button and see if they really feel similar. No need to go to the vastly different stalk.
For any normal person a button involves not only the application of pressure but also the consistent feedback of travel. Things like Apple's taptic engine and similar techniques simulate already bad buttons with microscopic travel.
I wrote more in the comment above but just to add that the old trackpad is not the best point reference. This is just Apple chasing thinness by making any button barely have any travel. Signal or wiper stalks have 2 orders of magnitude more travel.
I think the easiest way to understand the difference is to ask 2 questions: "can I put my finger on that button and not immediately trigger it" and "can I can physically tell that I am triggering it (ideally some physical travel)?" If the answers are "yes", then it's probably the kind of button people look for when talking about wanting "real buttons".