I don't know at what point the Broly movie came out, if it was before or after the Cell saga but I feel like the series lost so much of what made it special after Cell that it's barely recognizable or even good in most cases. Things became formulaic, the conclusion of most battles in movies and in following arcs became all too-similar and most if not all risk and danger that felt to critical in the first arcs of the story just lost all meaning and relevance. There's always a senzu bean, or a healer character or some dragon balls around. Any and all risk became a minor inconvenience and new more powerful enemies reach such a ridiculous level of power where they had to resort to gimmicks to try to keep things interesting except they didn't, they just repeated the same story arcs over and over in slightly different ways.
Broly's original appearance just happened to be the harbinger of things to come.