Is Word Count Still a Quality Factor?

Nope.

The number of word count on the page is not a quality factor or ranking factor. If we add more text to a page, will it go to rank on google?

No, it's not simple 

Think in this way. 

When someone searches on google "how to stay fit" It doesn't matter you include 5 steps or 20 steps. if your result satisfies users queries, then it will rank

is quality content means more word count

Quality content is not dependent on word count. 
When someone searches "What is white hat SEO? 

In this case, the User doesn't want a 2000 word blog post that explains what the white hat SEO is.

They just want simple information.

When someone search "keyword research techniques"

In this case, the User wants steps by steps process to perform keyword research.

so quality content depends on users' satisfaction, not on word count.

Google John Mueller Said:

“It’s a bit like if you want to present something to a client who’s walking in, you can give them a one or two-page brochure or you can give them a giant book of information.

And in some cases, people will want a book with a lot of information. And in other cases, people want something short and sweet.

And that’s similar to search.

If you have the information that you need for indexing for …kind of making it so that users and Googlebot understand what this page is about, what you’re trying to achieve with it uh… in a short version then fine, keep a short version, you don’t need to make it longer.

Is less word count means thin content?

Thin content means content that lacks usefulness. Thin content is not limited to word count.

Improve your articles for better ranking

Before improving articles, ask yourself a question.

Is this article full fill the demand of users. 

Some articles lost ranking because the content is going to be outdated as the year passes. So think about users, when improving articles.

Explore what John Mueller Said about word count. Start videos from 20 minutes