There is a semi-valid use case in that proxying your network usage through arbitrary hops is valid for anonymization and privacy.

Things like Apple Cloud relay and other corporate VPN services do make it more difficult for the services my company purchases to find your identity and track you. We are trying to find out how we can continue to prevent credit card fraud while supporting customers to continue using such services to protect their data and privacy.

Literally everything else is malicious though. The purpose is literally just a botnet. The point is to be able to get arbitrary packets stamped with arbitrary and diverse IP addresses to prevent IP address filtering and tracking from being able to block malicious activity.

It's ban evasion.