Your post made it click for me that Nintendo's platforms make it where there's legitimate reasons to use different controllers regularly. I use the Pro controller, a Gamecube controller, and the joycons/wiimote all for different game types, and sometimes switch between two in the same game.
If you were to ask me whether I thought this was a good design concept, having never played any games on a Gamecube>>>Switch I'd say no, that seems wasteful and a cash grab on peripherals.
But I love it. Give me more ergonomic plastic things with buttons and games that use them.
The Pro Controller is a fine controller and sees a decent amount of competitive use in the Smash scene.
The octagon gate on the GC controller is advantagous for Smash and other games that benefit from precise directional inputs... It's to the point where there are Pro Controller mods to add an octagon gate. The Pro Controller analog seems to wear out faster than that of the GC controller and it's a tricky replacement to perform (on an already expensive controller).
That doesn't happen for any other game, but there is just so much muscle memory for that specific game.
Also I still have a wavebird that is alive and kicking, shame it lacks rumble.