It would be simple enough to build visually exact replicas of TNG consoles with modern touchscreens installed and direct the actors to slide or expand images with their hands.
And yet, they didn't. That's not how the tech was shown to work.
There's nothing in the basic design of the technology that would prohibit that; it's just a matter of execution. What we're seeing is not reality, but a simulation of it.
I prefer the term "fiction" to "simulation."
There is nothing in the "basic design" of the, uh, visual layout of the "control interface" of a 1955 Muntz console television that would prohibit it from working as you describe the LCARS.
See those big ol' bakelite knobs? They're touchless sensors like the antennae on a theremin. Or maybe trackballs.
But of course it couldn't work that way - and
LCARS didn't work at all. The way they
pretended to use it was identical to any push-button-and-video-monitor home computer interface of the 1980s.
They did pretend to have a voice interface, of course, which makes it as advanced as what we do now with our phones. That was cool, just as cool as it was in the 1960s series.
No mouse, but Mike included a circular graphic element on the flat user console elements that can be read, and probably was intended, as a simple trackpad:
Nothing about its appearance suggests that it would be used to interact with anything other than a two dimensional display.
That you can extrapolate (here, I prefer "make up") more elaborate ways for LCARS to have worked that better suit your expectations is not the same as their having existed or, in most instances, been intended to be represented, by the initial graphic designs of the 1980s television series in the show's establishing seasons.
