Human signals are a lot more important than number of words.
Google is tracking your behavior 24x7 not just the static page any more.
It's all about machine learning.
If people reach your page and stay there 2 sconds and leave, it sends a bad signal. If they stay until a reasonable time to read the article and move to other pages, it's a positive signal.
Google then compares this to other sites in your niche. If people stick to your content 3 seconds more than competitors, you rank higher.
It's all about human tracking. Google is tracking everyone like mice, they know what people are doing online, that's how you rank in 2018.