How do I report fraud or App Store rule violations outside of a refund context? I'm not a developer, and I already used the "reportaproblem" link which doesn't help. It specifically hides any purchases made before the last 90 days.

I already read How to report App Store rule violations? and that didn't help one bit.

In particular, I want to report an app for an App Store rules violation and it appears that Apple blocked off all standard support routes to save money or something. In this case, the rules violation happened in an update years after purchase (so reportaproblem doesn't apply).
Fraud should be easy - engage a lawyer and/or your local small claims court. If the fraud is contract based, monetary remedy Is likely from small claims court in your jurisdiction at little expense to you in time or legal fees. 

For wanting to police Apple and/or developers on what you find to be in violation of Apple policies but not actual laws, I stand by my answer to the question you linked. 


Unless you have a developer relation and another developer is infringing on your work, you (the consumer) can only really ask Apple for a refund or just delete the app and send them general feedback when the report site has an explicit 90 time limit documented. 


If you feel you have an exceptionally serious issue, why not engage store support chat to validate how Apple would want to hear about the specifics?


https://support.apple.com/contact