2. The ground of the court must be flat and soft, with the principle of not hurting athletes and not affecting the normal operation of the ball. The FIFA World Cup Organizing Committee has instructed that the World Cup should not be held on artificial turf.
This is what Baidu said. Add some points. 3. The lawn quality of the stadium is better, because athletes usually hold some celebrations after scoring goals, and the poor quality can't stand it. Moreover, it is said that giant clubs like Real Madrid and Chelsea have heating pipes under their lawns to prevent the grass from freezing to death in winter. The stadium can accommodate a large number of people, and it is better to have several exits to prevent the fans from rioting.