Its that they waited till legends to bring up shrink.

If the modern day Sycamore told me that in XY at the time I first saw pokemon shrink as they fainted, it would have been an easier pill to swallow.

Instead I saw it for what it was, and still is: a garbage translation of the fainting "animation" from the 2d games. In 2d our brains just go "oh they fell over or whatever" literally no one went "oh yeah its them shrinking"

They only bring it up now because they needed to make up for the balls not being high tech anymore. You can't hand wave it as much when we know it only takes a rock and a fruit. Yes we know since gen two pokeballs can be made with fruit so why didn't they just mentioned shrink in-game back then as well.