There will always be retro addicts, but in decreasing numbers. I mean did you ever try and mention a C64 to your niece or nephew? Their retro means Sega Genesis, maybe even Super Nintendo. Most have no interest at all and beevr will be exposed to what we grew up with. Or at least those here old enough to have bought a C64 or Amiga new.
Mega Drive and SNES are retro machines but the definition of the term retro is different between people in different age groups. Today, we tend to like to use the systems we used during our "active" computing experience years, or we grow an interest for old computers, just in order to use what we've missed, or for other reasons. There is difference between two groups, I have friends who have used amiga and still like the old amiga games but for example, they aren't interested in MSX for they value their memories, not old computers themselves. Our Amiga enthusiasm will die with us, then amiga will be a part of the history. I do believe computing will be taken more seriously in the future though. In a hundred years, people will examine this forum and will try to understand why we were having all these conversations, maybe retrocomputing will be a rising trend after that