Important point. It's not actually all that trivial to give a good and safe lead belay with a grigri. I see folks wrap their thumb over the Grigri cam to pay slack all the time. It is extremely dangerous when combined with not paying much attention because a surprise fall will cause the belayer to seize their grip on the device and lock it open. Heart breaking example https://www.youtube.com/watch?v=WBGkKqLhM8Y

All that said, I still prefer to be belayed with a grigri.