The primary use-cases for using provider-independent (PI) IP addressing are as follows.
- To facilitate multi-homed connectivity
- To simplify migration between ISPs
The only benefit to using provider-assigned addresses is to the ISPs – it saves their hardware resources because they do not have to learn new routing prefixes.
Once the RIR provides the addressing, the organization is also allocated an AS number for BGP configuration.
Stuck-in-Active: Journal of an IT-Network Administrator 