So as of like, a year or two ago, Beyblade came out with a new system that used 4 pieces.
A Plastic Piece + Facebolt (Energy Ring)
A Metal Wheel (Fusion Wheel)
A Plastic attachy part (Spintrack)
and a Tip (Performance Tip)
So, these come out in Japan first, through Takara Tomy, which is p much like Japanese Hasbro.
Hasbro gets them in America. Aside from really shitty name changes (Gravity Perseus becomes Gravity Destroyer? Ray Unicorno becomes Ray Striker?), they do a pretty good job of faithfully retaining the parts.
Until the 4D series.
4D is new in that alot of the sets have "mode changes", where the Fusion wheel is broken into multiple parts, often a Main piece, a PVC ring, and a smaller metal ring that is often rotated to get different effects.
Hasbro said, no, fuck that. It's all one piece.
There's also new Performance tips that are the opposite, fused together Spintrack and Performance tip, often with really unique gimmicks.
Hasbro said, again, fuck that. We use older pieces.
So basically they decide to be lazy and fuck up the new sets.
None of the multi-part Fusion wheels remain, instead being one piece. None of the one part fancy 4D tips remain, being older parts.
And you probably saw the big question in the topic title.
Hasbro is like, fuck that, we want toys that 5 year olds will buy for no fucking reason.
"Hey, so let's take our tops, make them out of rubber, and flip them turnways. Flywheels totally wasn't a failure, right?"
(Also look at that douchey face the guy on the right is making.)