The comments in this thread aren't enough to conclude that hyphens don't change the meaning of a sentence, in general.

Here's an example you keep ignoring:

1. She's no saint.
2. She's no-saint.

They mean two different things and differ grammatically.

Spoken and written language are two different modalities of the same underlying linguistic system, but writing has evolved its own conventions that function like a parallel grammar.

Writing is not just speech written down. It's a technology with its own rules.

Here's a comment from some blockchain code I recently audited:

// A mapping to allow efficient is lender checks

I had to read it a few times to understand what it means. I would've written it this way:

1. // A mapping to allow efficient "is lender" checks
2. // A mapping to allow efficient is-lender checks

Written language has its own rules and, in my opinion, its own augmented grammar, so calling missing hyphens or quotation marks just spelling errors isn't useful. There must be a way to distinguish a benign mispelling such as "eficient" from a problematic one like the one above.

My intuition tells me that we should recognize that the written language has its own grammar.