Fans have been saying this about young players for as long as I've been supporting city, particularly strikers. It's because they can't see the class gulf between and EDS player and a Champions League player.
For a club like City to spend all those hundreds of millions on an academy and all those staff, and player wages, and scouting networks, and player attraction strategies, and medical teams, and education, and psychologists etc, and then not bother to try to get them into the first team is utterly ludicrous and would, of course, never happen.