One thing that always annoyed me is that they made the plastic balls larger and heavier at the same time they changed the material. At the time, all ITTF said is that they are simply enforcing the actual rules more strictly, since most 40 mm balls were actually about 39.5-39.7 mm. Yeah. Maybe. But why was that seen as something necessary?
Because they want to slow the game down.
Who knows why? But they never acknowledge that this was their motive. I find it hard to believe that it is to improve TV watching giving the crappy video feeds ITTF provides!
The switch to non-celluloid materials, I can actually see reasons for that related to factory safety. Chinese lives matter. I don't think people should have to risk being burned to death in a factory explosion so we can have ping pong balls.
But some the biggest problems we have with the new balls, including egg shape, fragility, lack of speed and spin, relates to their larger size, and not the materials. And that was completely unnecessary.
By the way, one reason that people like the Nittaku Premiums best is that they are clearly the smallest and lightest balls*. There are other reasons too why those are good balls, but their size and weight is a major one.
* You will read in some places that they feel heavier, but that is not true, I have measured carefully with a sensitive laboratory balance. They are harder, not heavier.
** And relating this issue to the Weickert vs. Saive issue on another thread, the thing I don't like about Weickert is his role in this, and his tendency to not speak openly about what ITTF is up to. Like Sharara, he is not transparent about what the ITTF is up to. Sharara would often say things that were demonstrably false in order to justify an ITTF decisions made for some other reason, like they were banning boosters for health reasons. Weickert has that same tendency.