Nothing has changed, it is just now, more than ever, specification is everything.

It is just that for some decades now it was possible to get away with poor or lacking specification, by continually incrementing by sprints, or pivoting, or whatever.

But, back in the day when systems analysts were still a person with very particular skills that might never code, specification was everything.

And now, the wheel turns, and the importance of good specification appears to be the defining factor once again, all of a sudden.