A benefit is in being able to predict who has — or will develop — the various skills, abilities or traits. Good tests need to be relatively objective, reliable, valid and standardized. To the extent that they do not have these qualities, these could be drawbacks.
I searched Google under the key words "testing advantages disadvantages" to get these possible sources:
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.
I hope this helps. Thanks for asking.