I have read a fair share of posts on this topic. I have actually, actively searched this topic to find out if there is indeed any said "number of words" that are guaranteed to bring in more traffic and shares.
But then I realized something very basic. There is no rule, engraved in stone, as to the number of words each posts should have.
Posts are written across genres, industries, tones, and with different intent and messages. Some readers like information which is detailed and has a lot of supporting information along with the main article. Others like crisp reads which are succinct and convey the message without other distractions.
Many a times, readers are also put off by the number of outbound links that one can find in an article. You know the ones that link you to another article for more information and so on.
I went ahead and asked my of peers (an informal survey) as to how many outbound links are they ok with, on each article, to which I received a range of 2-4 maximum. This was for a 500-word post. However, I feel the lesser the distraction, the better it is. Of course, it is totally up to the reader to opt in if they want to enhance their knowledge by clicking on those outbound links.
WP blogs mention that a blog should be at least 300 words long. It is understandable as whatever information you might want to share will take up at least 300 words.
For example, if you were to share an infographic in your blog post, it is always good to have the information in the info graph in text format as well, to make it more SEO-friendly. Of course, you are going to add an AltText to your infograph, as well.
Coming back to the point of number of words to be written for each article brings us to the topic of relevancy.
If it is a topic that needs a thorough foundation, examples, supported quotes and articles, flowcharts, then you can go ahead and write as much as you can to make sure your readers understand the topic well, which is your intent.
On the other hand, if the topic is such where you are sharing a few thoughts and pointers, it is best to be keep it in a bullet format, easy to read, process and store in the brain.
It is always advisable to add texts for video and picture-based articles. Just like I mentioned above, to make it SEO-friendly.
Finally, it doesn't really matter if your post is 1500-word long or 300-word long, as long as it conveys the message well. The number of words you write should be totally dependent on the topic and the information you have to share.
Don't let the binding of a said number of words put a leash on your creativity and flow. Go ahead and create some great and exciting content.