Actually S3 is a good example - it became the new de-facto standard for object storage management, and is used both by open source projects like minio and other clouds alike. This benefits the users/customers as switching from AWS S3 to another solution is a bit less painful.

What Amazon did with AWS, offering access to compute, storage and other services, was a good thing, and many EU cloud providers are implementing a small subset of their core services already. It's a good thing, there are no downsides really.