The $100 merely serves as a gatekeeper to prevent people and non-devs to create unlimited developer accounts. It used to be $500 a decade or two ago, and it was worth it even back then, until Apple realized they should probably just give it away almost for free.
The irony is thick. The dev is paying Anthropic $200 a month, but $100 a year for code-signing is extortion.
That isn't irony. Paying $200 for a service voluntarily is different than being forced to pay $100 because they made a rule that says you have to pay them $100.