Although outright opt-out isn't possible, it seems like heading to Accessibility -> Motion -> Reduce Motion (on) and Prefer Cross-Fade Transitions (On) reduces the effect.

I'm not sure if this reduces the buggy artifacts though.

Who decided things that slide in place need to jiggle like jello?!

I've been describing it as if the ui has been covered in corn syrup; like it has been drizzled in a slow and sticky and slightly blurry layer of transparent obfuscation.

Necessary has never been the deciding factor for Apple’s decisions, especially when it comes to design. Nor has “optional” ever really been part of that discussion. They know, like most people, supporting multiple interface simply creates more BS to maintain for the few resistant people who don’t accept change. Like it or hate, you bought an Apple.

I don’t particularly like it either — reality is what it is and if I don’t like it that much, there are other phones I can buy when I upgrade.

I can't remember windows vista actually making content illegible or reduced the content area in a focused window like Apple has done.