One thing I've noticed in my three years of chugging through so many Precure seasons is that some episode ideas tend to be reused in later seasons. They've also reused a number of plot ideas in general, such as having the mascot critter turn out to be royalty, or a significant plot device.

Both Fresh and Smile Precure had an episode dedicated to the mystery that is Manzai comedy. Both starred a real life comedy duo.

Smile and Doki both did the "Trapped in a Game World" thing. I think Yes Precure 5 GoGo did that too, but it was more of a game SHOW, haven't seen that season.

They didn't wait very long to have a villain turn out to be the parent of a Cure. But at least Suite handled that better than Heartcatch.

And of course, if you're a queen or adult princess in Precure, chances are you'll either end up dead, or have been dead all along.

I don't blame them for using reusing ideas. The series has been running since the 90s and it's probably going to go on as long as it sells toys. Plus the kids who watched let's say Heartcatch are probably not watching Precure anymore. There is basically a new audience every season because kids can out grow shows real quick. But is not an excuse? No it's not. They should retire the concepts they have done to death like redeeming a character.