Psychological disorders in kids

I’m a child of the 90s. I was “weird”—I wanted my blankets turned a certain way before sleep, I had to kiss all my stuffed animals goodnight, I’d wake up to brush my teeth if I forgot, hated sticky things, etc. That was my personality. I got over it.

Now I see in a FB parents group someone asking about similar behaviors in their 3.5 year old. Everyone is suggesting the kid has OCD, autism, sensory issues etc.

Why does everything that seems to “fall outside” the norm or convenience for a parent get labeled as a psychological disorder?

I’m not saying some kids don’t have these. But is it possible like, most of them do now? Why is this? It seems to often lead to medication etc.

What’s the deal?