Payment facilitator model implementation might be a profitable step for many present-day software platform providers. If a software platform provider starts offering merchant services in addition to the platform itself and assumes responsibility for merchant onboarding, provisioning, and funding, as well as for reconciliation and chargeback handling, it removes part of the “load” from the shoulders of the underlying processor and even allows it to save some money, time and effort. In return the processor might share a part of merchant fees with the platform provider. If net volume of these savings offset the respective development, support, and maintenance costs then transition to a wholesale ISO or a payment facilitator model makes sense for the software platform provider.
If you want to learn more, you are welcome to read our respective article on the subject on Paylosophy.