because they're the creators favorites, both at RTG and at CDPR, they're also the examplar characters, Johnny is THE Rockerboy, Morgan(who is an odd duck out still in 2077), Santiago and Rogue are THE Solos, Rache, Spider & Alt are THE netrunners, Saburo Arasaka and his family is THE corpos/execs. If you pick up cyberpunk 2013 (if you can find a copy), 2020 and Red, all of them star those characters to a certain point, showing both favors by the writers and more over what "high level" can look/be like. and it's only more ridiculous in the now retconned out of Canon, Cybergeneration where those characters became literally mid level superheroes leading a generation of basically a mix of mutants, metahhmans and iron man styled teenagers against the corporate machine. To top it off due to cybernetic enchantments and other health treatments, 80 (as rogue and Adam would be) is the new 50, 100 is the new 70 and 150 is the new 80 (as Saburo himself shows)
But why not make the game 2025 or something then and have the story revolve around the aftermath of the tower attack without retconning. I said nothing about their age so I have no clue what you raging about.
Instead of this stupid "you have a time limit" story that makes no sense when you don't actually have a time limit, you could have a job to steal Johnny's engram for Rogue as the final mission. Not as a magical biochip, but just the engram. Or something else along those lines.