You could probably draw a parallel to computers. At one time, toggling in boot code using switches to get your machine running was a necessary skill. Not to mention writing your own code to get anything done. And many years after the "toggling in boot code" was a thing of the past, you still had to set jumpers and dip switches on hardware add-in cards on your computer (IRQ, I/O address, etc). Today many don't even need a keyboard on your computer (many people get by with just a tablet or phone for most / all of their computing needs).
> Today many don't even need a keyboard on your computer
And yet tablets/phones offer software keyboards because they're not obsolete yet. But that's a tangent, and I get your point.
And it's not an unreasonable point. But we're not there with cars yet. At least not those whose engines still include a link between the accelerator and the engine.
For example, I can see why knowing your RPM in a hybrid would be useless, since the motor/engine combination is entirely controlled by a computer (I still wish it was there, perhaps only because I'm used to having that information, and I feel poorly equipped to drive the car well without it).
But in an ICE vehicle, even a modern one, you still have surprising amount of direct control over the RPM. You also have control (or at least pseudo-control) over the operation of the transmission in most automatics. Even my CVT Subaru has the ability to override the CVT and set my own gear.
All this means that you can still operate the vehicle at or above the "unsafe for the engine" line... You still need insight into how quickly the engine is turning over.
