Mostly on the Mac. The butterfly keyboard and how Apple handled it, were terrible. And macOS quality had gone down release after release. But I have never had any serious software or hardware quality issues with the iPhone, Apple Watch, AirPods or any other products. It seems that they had just lost focus on the Mac.
However, the Mac seems to be rebounding. I have a M1 MacBook Air and it is stellar - probably their best new Mac in decades. Also, I haven't had many issues with macOS 11 so far.