Right but if this were the case then why does the Bandwidth Alliance allow you to move data at a much lower cost for 2/3 of the major cloud providers? If they _really_ cared so much about not allowing you to do processing with a third party, the Bandwidth Alliance wouldn't exist!
AWS is the sole hold-out here, and I think the way that Cloudflare worded this makes it pretty clear that the Bandwidth Alliance is basically a middle finger to AWS than anything else, but it also seems clear that the cloud companies aren't actively trying to make it costly to do data processing on a third party.
In fact if you want to move off GCP right now, Google will waive all egress fees to do so: https://cloud.google.com/blog/products/networking/eliminatin...