Note that there are four different USAA insurance companies. Your military rank and how you got referred for membership will determine which one you join (listed highest/best to lowest):

United Services Automobile Association - Officers and senior NCOs

USAA Casualty Insurance Company - Enlisted (E-1 to E-7) and children of the above

USAA General Indemnity Company - National Guard, Reserve

Garrison Property and Casualty - Extended family of the above

I can't get past the article's paywall to view the 51% rate, but I expect your claim process experience will vary based on which company is insuring you.

I have noticed that the quality of service has declined over the past 5 years or so (which lines up with Peacock's being CEO). It sometimes takes 2 or 3 calls to answer a question with my policies these days, as they now have high turnover in the call center.