It is your opinion that they are "stale" when serious. I found it interesting to actually see the competent trio that they were originally hired to be.!!!! Oh dear lord. Didn't you understand anything I said? Why is this so hard for you?!
Let me break it down. TRio can be competent, fly away every time with their silly little jet packs, yet still maintain their character that they had in Sinnoh. Or is suddenly their personality what you find so unappealing, that you'd rather have those more-or-less stale villains appear for a few minutes, mostly fail their mission, and fly away?
But mind you, Team Rocket is never supposed to succeed. This is Pokemon, not some psychological anime where the watchers are made to believe that the evil team will lose, but in the end they'll get their way. Team Rocket, all villainous teams will bow down to King Ash and his hacked Pikachu at the end of the series anyway.