>>49816535Kanto and Johto were non-linear and basically had no story at all which can either be a strong point or a detriment depending on your taste
Hoenn and Sinnoh had more cutscenes and dialogue but the region was also very interconnected, meaning you had to regularly backtrack and revisit places you've been to with new abilities kind of like a top down lite metroidvania. I'd say Hoenn did this a lot better than Sinnoh but regardless while you were progressing at the game's pace you still felt like you had agency
Gen 5 is the first part where the entire game was just a straight line AND the story was a bigger emphasis. You had good exploration still but the progression was still linear and the story made me feel like I didn't have the freedom to do anything.
While the story emphasis was progressive, you can see a big noticeable jump from Gen 4 to Gen 5 and the series never really recovered.