I was about to respond and post almost the exact same thing - there are more "retro" / nostalgia shows now than there have ever been, and it hasn't slowed any of them down... (case in point, Stranger Things.)
It makes more sense - how much free roam the kids have, the lack of cell phones and good technology to transfer information easy, the lack of good forensics to make more of the clues / puzzles work, not to mention the classic vehicles.... they would be arrested for trespassing and snooping so many times, parents and law enforcement and other authority figures would not be allowing the access the classic characters get. No one would take them seriously. The characters really only work in an old school setting, IMO. If they ever made it far enough to do a classic Tom Swift, the aesthetics and "technology" would be very cool to look at, very steam punkish or atomic age or whatever you want to call it, and it is all absolutely a core part of the entire thing. I'm sure I could have said all of this more eloquently....