SwiftUI and probably Liquid Glass preceded slop. It's a larger cultural/management issue within Apple.
Back when it was obj-c with cocoa the quality was night and day higher than it is today. Not too long ago I booted my G4 and was stunned by how responsive it is, which was extra surprising considering at the time it didn’t feel that way!
You can tell that generations of greybeards at infinite loop have been retiring. They got the hardware culture right only to see the nextstep legacy in software go to waste.
The quality drop around the time it was introduced was staggering. One example: In the Objective-C days we had extensive, reliable and up-to-date documentation including entire developer guides (book-length PDFs) for all aspects of the OS. These days, besides half-broken frameworks and missing docs, you're lucky if you find out how things work from a WWDC video.
How can one argue against the disaster that is Tahoe? What kind of engineering culture not only produces something this broken but pretends it's OK? Jobs would have fired half the OS division for something half as bad.