Participation trophies/ribbons are detrimental to children's sense of worth. As a result of such proliferation of participation trophies & ribbons, children learn that they don't have to put in the time & effort necessary to succeed. They also believe that them are enough in or of themselves. They actually may become anti-achievement because they believe that such is totally unnecessary on its face.
The world doesn't work that way. The world rewards those who put in the time & effort to succeed while it disdains those who refuse to put in the time & effort to achieve their goals. Let's add that this proliferation of participation trophies & ribbons cause children to be lulled into a false sense of winning. It even results in becoming entitled. The premise is I am here & that's enough.
However, children will be unpleasantly surprised where they enter the real world of competition. Not everyone gets that trophy. Those who work smart will win while those who are mediocre or worse will lose. That's life & children should be exposed to competition early. There's nothing with competition for such builds character & strength.
Back in the days where there was competition, children were better off. They knew the definition of hard work & that hard work is rewarded. Competition builds a work ethic in children which lasts throughout their lives. Competition makes children better people & makes them use their potentials. In the real world, there is always going to be someone who will be #1!