[tehbeard]

≥ old keyboards used to have most of these buttons

Hmmm, I only recall one previous "proper" keyboard having OLEDs under the keycaps...

Slightly facetious, I know, but I think one key element you missed is the adaptability.

Yes keyboards used to come with calculator and mail and internet buttons, but often times you were stuck with those options only, or worse, the particular apps hardwired in the drivers.

Not only can this solution adapt to what you are doing / context aware, it can give feedback. That mail button can pull and render an inbox count. Online contacts profile pics can display in a select few buttons when they are available.

Price/gamer tax on this type of solution and how useful to the average user, that's up for debate.