Google’s algorithm can measure many things, but it can’t track is the smile on a reader’s face. Consequently, there is no easy way to measure if a given piece of content is adequately answering a user’s intent. One element that Google does measure is the amount of time that a user remains on the site (known as dwell time).
One method of increasing dwell time is to naturally write longer content. Because it takes longer to read, your average dwell time is going to reliably increase. In that same capacity, it’s also why many individuals recommend video content.
The other benefit of long-form content is that you organically include related phrases and synonyms, which gives you the opportunity to rank for additional keywords.
Last, but not least, longer content is performing better in search. Brian Dean released a study in 2016 that showed the average first page search results was 1890 words (from a sample size of over one million queries).