When AWS rolled out plans to start charging for IPv4 addresses:

https://aws.amazon.com/blogs/aws/new-aws-public-ipv4-address...

"As you may know, IPv4 addresses are an increasingly scarce resource and the cost to acquire a single public IPv4 address has risen more than 300% over the past 5 years. This change reflects our own costs and is also intended to encourage you to be a bit more frugal with your use of public IPv4 addresses and to think about accelerating your adoption of IPv6 as a modernization and conservation measure."

Their move disgusted me and I moved from AWS to OCI.