All of those buttons in the image you linked are labeled. What do you find confusing about it, and how would a touch screen make it any less confusing if you don't know what the labels mean to begin with?

The labels are mostly just one word, so not very helpful. That conference button, what does it do? Will it ask me to type in the phone numbers of to-be-invited participants?

Also the buttons are not context sensitive. Ideally they should disappear when you can't press them. I want a basic interface with clear options, and unfolding menus whenever I want to do something more advanced like making a conference call.

Well nowadays tough screen controls have no affordances, it's not even clear what areas can be pressed, much less what actions it will engage.

>The labels are mostly just one word, so not very helpful. That conference button, what does it do? Will it ask me to type in the phone numbers of to-be-invited participants?

How would a touch screen change that?

>Also the buttons are not context sensitive. Ideally they should disappear when you can't press them.

Ok, so you enter a menu and now you have a "conference" button displayed, but you still have no idea what it does. I think touch screens are useful for actions that require a lot of interaction like entering navigation, but removing physical controls for basic inputs like volume knob or HVAC controls is an obnoxious anti-pattern, especially Tesla moving the wiper controls to a menu. Dirty windshields and worn out wipers are enough to make auto-sensing wipers act inconsistently. Removing the physical controls from them is a stupid fashion choice, much like Jony Ive screwing up the MacBook pro over the last decade in the name of design.