i am sorry, none of you have any idea what it takes to come to the net all the time. You have to set the point up to do that and we do not know the pace of the ball coming to Andy to what he can do with it,
You only know this if you play the game, and that is at our level, think of this at his level. It is not easy. The first serve is very important and that is why raonic beat Andy. Serve is the key in Singles. If all is going to song then he will play well.
In singles you ahve to have a good serve at all times and that does set up the next point.
It definitely wouldn't be a good idea for Andy to come into the net all the time - you're right it would be extremely difficult to do that. Serve and volley would be very risky. But there's definitely room for Andy to come into the net more often, and it doesn't always have to be high-risk tennis either but is a good way of shortening rallies when the time is right.
I agree that the serve is key to Andy's success, though in the Raonic match he did serve well - it was the first serve return which wasn't working that well.