Would you rather go through the process during your pre-production development or after you've launched and run into a problem that you can't easily resolve?
I agree that the certification process can sometimes seem overly complicated, but it really is better to make sure everything is going to work prior to moving into production. I would recommend find an organization that can help you through the process. It's a little more work up front, but you'll end up with a better, more reliable product down the road.
Typically, when an operator requires certification, they are testing the performance of the device on the network. For example, they may test how your device performs in fringe coverage. It's important to note that PTCRB does not include some of these network performance tests, so you could pass PTCRB and your device could work poorly in some areas. Certification is meant to make sure you are delivering a postive experience for the end consumer, which is going to help your business AND the operator's. While it's often harder to pass operator certification than PTCRB, it's worth the effort.