Kirby planet robobot is often considered the best kirby game. I agree
The thing is, there's not a major difference between it and other "modern" kirby games, but what makes it genuely good is the polish. I couldn't find a major flaw that made my experience worse. And the esthetic and the robot while not upping the score, make the title way more unique and different does making it stand out above the rest. Excellent experience, it reminded me of why I like kirby.