Are they cheaper? I don't understand the point of them in the cases where they're literally just replacing a real button. The worst is when they don't even indicate clearly where the buttons actually are.
Not generally, by neither are they more expensive generally.
However, there's a large section of consumers that see that sort of thing and somehow assume it means the product is of higher quality, or that's what comes up in the marketing meetings I've had to sit through whilst advocating for mechanical switches.
Product designers hate mechanical switches because they are almost always the first thing to wear out. Including a switch robust enough to last as long as the rest of the product is generally too expensive for consumer electronics.
Capacitive buttons can be made much better with some kind of instant feedback to replace the tactile feedback of physical buttons.
The problem is that adding that kind of feedback costs money. Even if it's just a few pennies per device, most manufacturers won't do it for consumer devices. That kind of penny pinching is the reason I avoid consumer grade products if at all feasible.
Capacitive buttons have some distinct advantages too, primarily being waterproof and nearly infinite durability. A lot of UI issues like OPs stove are likely poor software, there is no real reason why a capacitive button would need a 700 ms pause between actions. Now, the lack of tactile feedback is a more fundamental problem sometimes, but capacitive buttons can be great when implemented well.
The problem described occurs before the oven even has time to heat up at all much less heat the input panel to 120F.
However resistive needs fine-tuning, and really shouldn't be used in dusty or hot environments. Which adds design time and shielding costs.
In our internal research, they end up costing about equal. But we are small, so it might change at a larger scale, though I'd expect those differences to shrink.
You also don't need to engineer attachment points into the product chassis, and assembly is easier.
In addition, they can improve the lifespan of the product because they don't wear out nearly as fast, and they don't provide ingress for dust and water.
Capacitive inputs have many downsides, but at scale they are certainly cheaper on average.
In your particular case they may not be cheaper due to other design considerations.
That interface was genius. These days I sob and cry every time I have to figure out how to use an unfamiliar microwave.
As for regular oven tops, we spent some time finding an induction model with physical buttons. It's wonderful and I enjoy using it every day. It's very tactile. Throw a kettle on and slam it to "P" in 30 milliseconds, aah I love it.
Both are on the fly adjustable, both power and time. I find it really good design.
They don't work any better or worse with wet hands, so I have to figure they kind of sacrificed overall usability in exchange for capacitive touch working with wet fingers.
My lab placed fancy touch-screens in the place of the light switches. Now turning the lights on or off takes at least 15 seconds but we get to pretend to be luxurious :(
You don't make sales based on how much people like using it, you make sales based on how attractive it appears while on display.