Millennial here: I think what Gen X and Boomer authors mean when they say ‘GenZ is more tech savvy’ is basically just that they use social media apps on phones and play video games, and that more of their culture derives from such things.
Maybe tech-immersed would be a better term.
As far as actual tech competency goes?
Yeah I agree with you. Phones and apps are generally reliable enough now that there’s far less need to figure out anything under the hood, unlike in my day where you kind of had to learn more about a system to do what is now common, and you had to type on a keyboard.