There is something professional about gaining possession, running along the touchline to the corner and struggling to keep it in bounds while defenders try to win it back. I have nothing against that. For players who fumble with the ball and roll around, that's where the ref should be adding time.
I mean timewasting when the ball is out of play. As long as it is in play, that is part of the game imo.
What I have a problem with is Mbappe's action last night. And especially because millions across the world look at it and you know what the reaction is? How 'smart' of him. That's really not what sport should be about.
I remember one instance this season with my own team when we were 1-0 down and the ball went out of play. The opposing team's manager had it in his hands and pretended to give it back to me. Then at the last instance he took the ball away again. I tried to grab it from him and he threw it away. Out of frustration I give him a slight push and I get booked. It's just one incident you might say, but it happens week in week out and I think it makes everything ugly.
I used to be strongly in favour of red carding players who waste time, but I think the problem would be with a case such as Matuidi last night. You're 90% sure he's wasting time. But maybe he really is injured again. You don't know. So I think stopping the clock would be preferable.