The physics prof who gave me my start would always get this kind of fond, nostalgic look in his eye whenever anyone mentioned "the days of punch card programming". So, naturally, I took an old slide rule and mounted it in a shadowbox with lettering that said "IN CASE OF EMERGENCY BREAK GLASS" when I got ready to graduate. He got a tremendous kick out of it.
Disclaimer: I'm just an...interested layman, but as far as I know we don't really know. It looks like there's both genetic and environmental components to it; your genes have a big impact on your "temperament" and more volatile temperaments correlate more strongly with cluster B disorders. But it seems like neglect, a failure to recognize a child as their own independent person (basically "my needs are your needs"), from parents/caregivers who are often themselves narcissists contributes pretty strongly, too.
The Little Shaman[1] has been one of the most comprehensive-yet-approachable resources I've found for understanding these kinds of high-conflict personalities. In particular [2-4] are pretty relevant to your question.
> I came across narcissism. The idea that you’re smarter than everyone else. Comes from a grandiose sense of self importance.
This may be the colloquial description of how narcissism manifests, but it isn't even close to (and possibly completely opposite) clinical narcissism. The grandiosity isn't so much a belief as it is a "false self" put on to garner caretaking from others. It's not "I got all the toys as a kid, so I deserve more stuff!" but a failure to individuate from caregivers. "Mom (as a tool, not a wholly independent person) came when I cried as a kid, so I need you to lavish attention on me and make me feel better now as an adult. I can't see myself without external input; I only see myself as a reflection through you."
I'll offer no commentary on whether "Sunshine Protection Act" is virtue signaling, but I think virtue signaling is less "talking about having done virtuous things" and more "talking about doing virtuous things with the intent to gain social capital". It's the facade, the ulterior motive that most people balk at. In that sense it has always been a "bad" thing.