overqualified

As a noun overachiever

is one who overachieves; one who has too much success.

As an adjective overqualified is

having too many qualifications to be deemed appropriate for a (usually unskilled) job.

As an adjective overqualified

is having too many qualifications to be deemed appropriate for a (usually unskilled) job.

As a noun overqualification is

the quality of being overqualified.