Is this readability stat good for SEO?

Yoast says this readability:

In my opinion, Yoast readability is a load of nonsense. I found it very irritating and is one of the reasons I stopped using it. They recommend writing something like 10-word sentences that are aimed for an infantile to read. I don't see how that is valuable for readers but I guess it depends on your niche.

It is just some random bullshit and so is the "SEO score"

didn't see any good improvement ever since i used it.

Just make sure that your content is of good quality and unique. All these SEO plugin metrics are attempts to quantify that. The reason to avoid the passive voice, for example, isn’t because it’s inherently bad, it’s because it can make your text sound stiff and overly formal, if used excessively. You should treat these metrics more like a rule of thumb, and look at the text holistically, not just with percentages. You can try and see what Hemingway Editor tells you about your text, it might give you some ideas on how you can streamline your, and that will have an impact on Yoast’s score.

Readability is useless for seo

You can make content is a good quality. Readability is not good for SEO.