macOS Tahoe is about to be replaced. After 8 months of improvements to rectify problems in its redesigned interface, what has changed, and is that sufficient to upgrade from Sequoia?

AppKit originated in NeXTSTEP and its menus, windows and views are usually built in its graphical editor. SwiftUI was introduced in 2019 and is built using code structures, but supports less than AppKit. Neither is without its problems.

Why isn't the progress bar for macOS updates better? Why can't it estimate the whole time remaining to complete an update?