Why has so much of the software industry stopped doing QA?

In the past few years, a lot of software/video game studios have decided to just stop doing QA. Microsoft famously fired almost all of the Windows QA people in 2014 or 2015 I believe, now we’re seeing video game studios like CD Projekt RED and Rockstar decided to stop doing basic QA on their games. There are more examples of this trend. But why have companies decided QA isn’t necessary anymore? It ends up hurting the companies reputation and their wallet too, so what’s behind this?