1GB of egress costs about 9 cents.
The cost savings is equivalent to ~$9/mo in standard US regions. Nobody is going to migrate clouds over a $9/mo saving.
If we're talking about CloudFront that comes out to $85. That's actually a pretty good savings, but it's distinct from egress. CloudFront's pricing isn't locking customers in due to egress pricing because it's a CDN, not a data storage service.