I'm not aware of any benchmarks. Neither am I aware of any performance deterioration in Safari 15.4+. What is your point exactly? That performance should be on

I'm not aware of any benchmarks. Neither am I aware of any performance deterioration in Safari 15.4+. What is your point exactly? That performance should be one of the most important aspects in browser engine development? I agree. Hence, I asked OP to elaborate their claim that this selector harms slow devices. And I'm not interested in the (outdated?) historical concerns of a parent selector. But the actual effect of the specific selector implementation in WebKit which this discussion is about.