It doesn't provide any information regarding the problem you have
It doesn't start a proper conversation. Calls require setting up hardware and achieving mental readiness
A call may not even be needed. The information you require might not be available from the person you want to call. Even better, this information could be provided faster without calling.
This is the key! First communicate your needs. Let the other side decide if more info is needed. Even a short discussion may lead to solutions.