Railway signalling and interlocking systems. Sure ETCS and other digital systems are far safer, but some dude at a junction used to manually reset the points and crossovers using a giant lever. Now everything’s just a digital system overseen by someone with 8+ monitors in a control room removed from the actual network.
Also, not a technology, but rally cars used to be fully unhinged. I could watch old Group B videos for hours and never get bored.
It’s just a prank bro, no homo.