When we create a VPC, we specify an address range to be used within our VPC as a CIDR block (mostly as 10.0.0.0/16). Then we launch instances within that VPC. And they will get private IP addresses from that address range. And when we create a S3 bucket and add some resources to it, we get URLs for those resources. if there is a URL, then there must be an IP address. Where does the IP address for those come from? from our VPC address range? Or is there a set of IP addresses within AWS to be used for S3 services without concerning about VPCs?
S3 IP addresses are consumed from a AWS-owned network range that differs based on the geographical location. Your our subnet IP's won't be affected by your S3 endpoints.
Indeed, the article below describes how to find the IP range for such a service,
https://docs.aws.amazon.com/general/latest/gr/aws-ip-ranges.html