I accept the qualification, but I stand behind my point.
Look at our current DLG gliders and competition sailplanes. Designed on computers, hollow molded from molds produced by computer controlled machines. Laid up entirely from ultra light and strong composite materials. Servos, rx's, gyros that are many generations more advanced from early r/c days, and you NEED a current design to be competitive.
Look at an FPV racing drone. Almost entirely a product of computer technology. Evolving in performance and capabilities at an almost daily pace. The only thing that they have in common with early model aviation is use of propellers.
In control line, Noblers, Ringmasters and Flight Streaks, are still popular. Cox .049's, Fox .35's and K&B .40's are still powering them. Sure, electric power, computer designed and produced parts, electronic timers, composite materials, advanced batteries, etc have modernized the sport, but control line design and technology from the 1960's to 1970's is still very much in common use to this day.
Control line IS retro.

That's a big part of it's appeal.