In the past, AWA score was not as important. However, as more students use admissions consulting service to have their essays edited, this section has become more and more important in an admissions decision. The AWA essays can be pulled directly from the system to be compared with your application essays. If the quality diverges significantly, it is certainly a red flag.
In general, if you have limited time prepping for the GMAT, then put AWA on the back burner. However, if you have sufficient time studying for the test, do take it seriously.
First, it is the first section on the test. If you ace it, you will feel good and gain confidence.
Second, the AWA questions are closely related to Critical Reasoning. The same thought process in argument analysis. If you are not good at AWA, it is possible you may not do well on the Critical Reasoning section.
Third, if you score over 700+, but your AWA is just 4 out 6, it does not look good in general. If you want to be a GMAT instructor in the future, 5, 5.5, or 6 certainly help more!
Fourth, adcom might compare them with your application essays.
Fifth, any possibility you can make yourself shine out of so many competitors, you should seize on it. If you have a 5.5 or 6 of 6 AWA score, it will only help you impress the adcom.
Hope this helps!