Apple have totally forgotten how to test and assure software against what appear to be even stupid bugs. macOS Catalina has been fraught with issues ranging from the minor to the ridiculous. Clearly nobody even bothered to test whether the Touch Bar "Spaces" mode on the MacBook Pro 16" actually works properly before shipping the thing. Software updates sometimes just stop downloading midway through, the Mail.app just appears over the top of whatever I'm doing seemingly at random and Music.app frequently likes to forget that I'm associated with an iTunes account.
Microsoft are really no better - Windows 10 continues to be slow on modest hardware and obvious and ridiculous bugs continue to persist through feature releases, e.g. the search bar often can't find things that are in the Start menu!
My question is who is testing this stuff?