Dwarkin
Because the other translators have their own books to translate. Would love to see you work your job then also do someone else's at the same time. Reality just doesn't work that way.
As for letting some random person pick it up, all they have to do is contact webnovel and sign a translators agreement, sadly random Joe dickhead can't be bothered usually with going through the PROPER channels so as soon as they try to steal webnovels business they get shut down and lose the chance.