They give you value for your $100. You get two technical support incidents per year: an Apple engineer will assist with code issues. They handle all necessary

They give you value for your $100. You get two technical support incidents per year: an Apple engineer will assist with code issues. They handle all necessary tax withholding in countries which require it. This is something you had to do yourself with Google Play (unsure if this is still the case). You also get access to CloudKit and various other Apple-hosted services which can be used within your apps. I don't doubt that they make a profit on your developer enrolment fee, but it's almost nothing in the scheme of things, and you are actually paying for something.