OS is a good example. Recent MacOS and Linux are easily the highest quality OSes that have existed. iOS and Android are quite good too. Unless you go back to when OSes could be extremely simple.
Is an example of a system going downhill fast. Critical bugs making it though whole beta into the final release. Hell remember https://www.zdnet.com/article/apple-patches-severe-macos-big... from just last year?
MacOS quality has been on the decline as the focus has shifted to iOS.