Interior controls moved onto touchscreens across the industry within about a decade. The reasons were mostly commercial, and the partial reversal now underway is a response to how the change worked in practice.
One screen replaces many parts
A dashboard full of switches is dozens of separate components, each requiring tooling, wiring, assembly labor and its own supply chain.
Consolidating those functions into a display replaces all of it with one part and a wiring harness, which is a substantial reduction in cost and assembly complexity.
It also removes variation between trim levels. The same physical dashboard can serve a base model and a loaded one, with software determining what functions appear.
Software changes are cheaper than hardware changes
A control laid out in software can be revised after production, which lets manufacturers correct mistakes and add features without touching the assembly line.
Over-the-air updates extended that further, turning the interior into something that can change during ownership rather than being fixed at build.
The same flexibility allows regional variation and feature packaging to be handled by configuration rather than by building different parts.
The cost is landing entirely on the driver
A physical switch can be found by touch, has a fixed position, and gives feedback when it operates. None of those properties survive on flat glass.
Using a touchscreen requires looking at it, which means eyes leave the road for the duration of the interaction rather than for the instant a hand reaches for a known knob.
Menu depth compounds this. A function two or three taps below the home screen turns a one-second action into a sequence that competes with driving for attention.
Safety assessment began accounting for it
Independent testing bodies started evaluating how basic functions are operated, including whether core controls such as wipers, hazards and defrosters have physical actuation.
Because these ratings influence buying decisions, they created a commercial reason to retain hardware for functions where a screen is genuinely worse.
Several manufacturers have since reintroduced knobs for volume and climate while keeping screens for navigation and configuration, which is roughly the split the evidence supports.
Where the balance seems to be settling
Frequently used, simple adjustments suit physical controls, because they benefit from muscle memory and need no visual confirmation to operate correctly.
Complex, occasional and information-rich tasks suit screens, since they need labels, lists and feedback that a fixed switch cannot provide.
Voice control covers part of the remainder, though its reliability varies enough that most designs still treat it as an alternative rather than a replacement.