There are some factual "gaps" there about how good Snow Leopard was, but I understand the sentiment. As someone who's been a Mac user since System 6 and has been consistently using Macs alongside PCs _daily_ for over 20 years I can say that Apple's software quality (either in terms of polish or just plain QA) has steadily decreased. It's just that me and other old-time switchers have stopped complaining about it and…
Spotlight is unbelievable bad, especially on iOS. If I type a substring of the name of an installed app, it should find it effectively instantly (say, within 1-2 frames of the input showing up). Instead, it finds it sometimes. On occasion I need to hit backspace (removing a letter that should match) to get it to find it. I struggle to imagine the software design that works so poorly.
Then you do a search for .jpg, and get NOTHING. But only sometimes. Other times it'll work.