There are several scenarios and more than one company doing these. I didn't have any drivers from Uber fail, some of the scenarios allow for delivery with them doing things correctly.
I think, in general, the vast majority of delivery drivers are going to adhere to the law. I am not sure what the percentage is who don't but it isn't zero. When you find one who has a certain attitude and you know they are breaking the law routinely? Well, I hope that being caught by a shopper motivates them to do better but losing their ability to deliver alcohol is also a reasonable consequence. I've been very surprised and disappointed more than once.