Also imo before he met Snakey he had real prospects of being a good Prince. He got involved with certain very worthwhile causes such as Lilla Barnets Fond. Emma was a good influence on him. Of course he never reached his full potential, but he could have. Since he met Snakey his causes, and overall work ethic, have been on a downward slope.
I feel like it's a combination of things. His work ethic has decreased not because of who she is, but more towards that he got married and started having children. In the meantime, Victoria has always stepped up with Dan, and so there is less of a need for CP. The older Estelle and Oscar get, the less CP and Sofia will be asked to step in.