Answer:
Expertise in 1 area
Step-by-step explanation:
If you had a general knowledge of literally everything, that is great for mastering school. But, you are not going to school your whole life. You need college, work, and so on. When in college, it isn't like school, you can only choose 1 subject. Thus, it is good to expertise in 1 area.
I hope this helps you :)