Where do they say ‘core platform service’ are the SDK and tools? I think you’re just making that up.

Here: https://developer.apple.com/support/core-technology-fee/

> The Core Technology Fee (CTF) is an element of the new business terms in the European Union (EU) that reflects the value Apple provides developers through ongoing investments in the tools, technologies, and services that enable them to build and share innovative apps with users around the world.

"Core platform services" is the term used by the EU.

I think you’ve shown the flaw in your own reasoning then. “Ongoing investments in tools, technologies, and services…”

It’s not just the SDK.

Is that supposed to be a gotcha? Yes, there's ongoing investment, that's why developers have to pay an ongoing, annual fee.