That does not seem to be true:
https://www.uber.com/us/en/drive/insurance/?city=portland
>When you earn with a transportation network company (TNC), referred to here as ridesharing, most states require extra—and costly—insurance.
>Uber maintains this commercial insurance on your behalf. What’s covered depends on factors such as who was at fault; whether you were offline, online, en route, or on-trip; and your personal insurance policy. Learn more about the commercial insurance coverage Uber maintains on your behalf below.