Google's "Helpful content" Update - What I've Noticed

I had some really good blog posts ranking on page 1 for years but now they are sliding off page 1
The only thing different about these blog posts is that they are 4000 word +
Well written content (not ai or spun)
My other blog posts (on the same site) are still doing great
Maybe Google hates long content now?

PS: I found this while searching info about the google helpful content update.

What are your thoughts?