The apperence of not having logs is useful for both the law enforcement and the VPN owner, so why whould they subpoena the logs? The VPN could leak some details

The apperence of not having logs is useful for both the law enforcement and the VPN owner, so why whould they subpoena the logs? The VPN could leak some details to the law and in exchange the law mostly leaves them alone. And the law would get cases where they know that spending their time will pay of: Saying "yeah, the computer repair shop found CP on the guys computer", thinking "because we told them where to look".