You can include capacitive inputs on a PCB in many cases for essentially zero cost.

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.