The reason why cars use cryptic symbols for lighting and similar settings is because these symbols are standardised and you (the driver) are expected to know them.

And in any civilized country where operators of heavy, high speed machinery like cars are required to get training from a professional (and not just like … their parents), you have to prove that (among other things) you know what those symbols mean to get a driver’s license.

And because these symbols are actually the same in every car (because that’s required by law), the knowledge of what they mean and how/when to use which settings applies to every car. That makes these symbols far more usefull than writing out what each setting does, both for space reasons, and for quickly recognizing which is which.