Search Engine Forums, SEO Forum

There is no certain limit for a blog post length as far as I know.

You have to focus on 2 major thing:

User Intent
Target Audience
If you can give proper answer to your reader query, your content is fine

Even if it is a 300 word length article but useful, you can count on it.
Despite of having 600+ word length of article with less engagement, it is not worthy to be counted.