I write a paper for someone else to turn in as their own? In a situation where I know more or less nothing about the client? The outcomes are both unknowable and in most cases impossible to tie to my act directly.

You breached academic code and, if money was exchanged, potentially the law. Given you wrote the paper and received the money, the act is quite simple to tie to you.

>potentially the law

Yeah, show me the law that tells me it's illegal to write something for someone else. Thanks.

Writing papers for someone else is not illegal. (The student presenting the paper as their own violates your copyright, and potentially other laws.) But if you market and sell your papers for the purpose of cheating, particularly with respect to students pursuing degrees they intend to use for licensing/certification (e.g. law or civil engineering), you're aiding and abetting fraud.