>>51636613More like after Orange Islands. A Johto arc featuring Ethan/Kenta/Jimmy would've not only been cooler, but likely not made Johto the filler hell it became provided the GS Ball arc was properly realized.
With that, I'd say mistake #1 was keeping Ash as a recurring protagonist and cycling the same plotlines for many years and mistake #2 was abandoning the GS Ball arc for the 4th movie, thinking the audience would forget about the former. We never forgot.