The author also makes this error, praising Apple's design prowess and denigrating its competition while failing to recognize they "didn’t always react the way I thought they would" because they're ill-suited to the medium.
And with traditional toolkits (i.e. not HTML) it will even be fast.
I can make a 16x16px knob where you can see almost the entire 320° of the range.
It's also easier to see fractions, such as 1/2, 1/3 or 1/4.
Sliders, especially in 16px possess none of those.
Being able to see the full state of the thing is important. Hiding it behind interactions is just as bad as hiding it behind menus.
Sidenote, you have to do this on native because pointer lock/warp is not universally supported in web browsers.
As others have pointed out, sliders have limits & knobs don't, so I do think they have their place on touchscreens.
If a digital knob needs to be turned several times (e.g. 1080º, common in DAWs), the "default" way to interact with a knob on a touchscreen - circling again and again - is slow and uncomfortable. Adding "slider" gestures on top of the default behavior is a nice way to perform many turns quickly and easily.
I'm curious - what UI mechanism would you use instead?