[drdaeman]

Why would one possibly need a SaaS payment processor for crypto? Unlike with traditional banking, running your own crypto node and processing network transactions is not some huge investment that one may want to offload to a third party.

[Muromec]

To offload dealing with problems (technical and legal) and risks to the processor. Like everything SAAS basically. If they get hacked, it's not your money being lost for example.