I think it just comes down to personal interests. Nothing to do with complexity or ability. It is a niche interest and while increased exposure will increase participation/interest it is NEVER going to have uptake like something which can be experienced on a mobile platform.
Pinball machines do not have the capability to immediately captivate a non interested audience. It takes a lot of work to draw most people in. Damn, I can’t convince any of my close friends to buy a motorcycle, play pinball or go skydiving - just not interested and I have been trying for 20 years. But damn they will try new IPA’s at the drop of a hat - now that they are interested in. They will play pinball under coercion and have turned down multiple offers to borrow a game. But at the end of the day - the interest is not there. My son and his friends were the same way. It either captivates you or it doesn’t.
I lost my interest in pinball in the mid eighties once video games really took over. My interest in pinball came back largely due to nostalgia (anyone can have a video game/emulator) but not just anyone could have a pinball machine. It was different and gave me an opportunity to tinker again (long ago were the days of rebuilding dirt bike engines and the like). It was interesting (to me).
Young people are not dumber or smarter than us. Anymore than we were our parents. Are they a different combination of experiences and knowledge - well yes. They are different than us, just like we were different than our parents. Remember we can’t build pyramids anymore but 1000’s of years ago we could. Are we less skilled? Less intelligent? No, but we’ are skilled differently and have significantly different interests.