S3 is a protocol understood by "everyone". If you're on AWS, as many are, it's basically the only natural choice. But a number of cloud providers, and a bunch of self-hostable software offer an S3 interface.

Clickhouse on local NVMe is one possible solution, but then you are married to that solution. An S3 interface is more universal and allows you to mix and match your tools, even though this comes at some expense.