I definitely agree that some conditions went undiagnosed or 
    weren't even considered a disorder [...] 20-30+ years ago 
    someone was just really into trains.

I always think about this.

I think we've gained much more than we've lost. I'm glad we diagnose more things. I'm glad we as a society have begun to accept neurodivergence in general.

But, I don't know, it feels like some things were lost as well. Labels and diagnoses can really hurt as well as help.