Actually this will also happen to players who have experience, I mean even though players who already have minutes to play in the first team, it is not a guarantee that they will play well. Likewise with what Real Madrid is currently doing, they are trying to invest in players who are seen to have great potential in the future. That's why they tried to sign him early to monitor the progress of this player.
Who can guarantee that in the next two years the player will still be at the same performance or will improve, because Endrick has yet to be tested in European competition.
Maybe Real Madrid's monitoring of the interest in young players saw something different from Endrick's figure, so they decided to take quick steps to secure the player, even though the player could not join yet, because La Liga rules do not allow underage players to join.
I want to see Endrick play at Real Madrid and hopefully he will be a great player in the future.
The gamble made by Real Madrid on untested young players can be profitable or vice versa. Real Madrid is trying to invest in young players who are still playing in the local league. So far, Real Madrid's scouts have been monitoring Endrick's development, they assess that Endrick has extraordinary talent. Endrick can be used as an investment for the future of Real Madrid, usually players from Brazil have good individual skills, it is impossible for Real Madrid to dare to spend money if there is nothing special about Endrick.
Many considerations made by Real Madrid before making a decision, so Endrick is considered worthy to be invested as a young player, Real Madrid thinks that the skills of Brazilian players can generally develop quickly, so the steps to secure Endrick must be accelerated.
But whatever decision Real Madrid takes, they gamble with that decision, because everything will become clear after two years from now, when Endrick actually plays for Los Blancos and that's when Endrick begins to be tested against the decisions taken by Real Madrid's management.