I agree that it’s not a useful metric to apply to an individual. “Ok boomer” aside, there is too much variation within a generation for it to be a useful way to draw any conclusions about a single person.
Where generations are useful is in demography. There is no strict dividing line between a lot of kids of demographics, but categorizing them can still give us useful data for studying populations
That might be me. I’m a millennial by age, but I have always been keeping up with the newer tech. My father worked for Microsoft so we always had the new stuff as soon as it was available. And I’m a weirdo little autistic trans girl, so I didn’t really socialize that much with my own age group even when it was an option.