While QCOM obviously doesn't have any problems right now because they're the biggest player in the ULP SoC market, it doesn't mean that their drivers are perfect or don't have any headroom for improvements. Au contraire ask any sw developer that deals on a constant basis with Android GPU drivers and you'll see that there are problems here and there, but they aren't easily solvable due to the nature of Android itself. Of course we can always blindfold ourselves and just claim that everything is perfect in the house of Denmark, while it isn't.