You - or anyone reading this comment - use E-Prime in a functional context?
I think the benefits come from using action verbs, and identifying actors, eliminating passive and weak expressions. A secondary benefit comes from removing implied identities: I don’t say I am a programmer, but rather I write computer programs. I recently argued with a friend who insisted D is a racist because I reframed that as D said some things many people interpret as racist. Focus on the action rather than the person, in other words.
E-Prime may change how you think about your usage and improve your writing, even if committing to it completely presents too big a challenge.
The example of racism cuts to the heart of it. What do people mean by "racism is bad"? When you say "Arthur regularly says negative things about black people" or "Cindy only hires other white people", you've said something much more meaningful than "Arthur and Cindy are racist".
You can't always include such details, and sometimes you want to say your point vaguely so that you can move on to the more important part. But awareness makes you look out for places where you do it inadvertently, or because you haven't clarified your own thoughts well.
For example, that last sentence started life as "I'm not perfect at it". The sentence above gives more information about what that means.
Sentences that describe what something does, rather than what something is, convey more to the reader. It corrects some of the same failings as the passive voice, which also obscures who does what. E-prime puts more emphasis on verbs and de-emphasizes adjectives.
The nature of English makes perfect E-prime impossible or awkward, so you should take it as more of a guideline than a rule. Certain tenses mandate to-be verbs, for example. We don't always have a verbal equivalent to some adjectives. The passive voice sometimes conveys nuance in exactly the right way, and the same goes for non-E-prime English.
But the guideline makes you aware of ways to be more concrete and specific in your writing, and the practice may even help clarify your thoughts for yourself.