What's best for your target audience? Would people read 2,000 words? Of course, it really depends on your site topic.

Let me try to explain: If you're writing papers for medical research you're probably going to have much longer documents.

Without knowing more, i'd probably lean towards more frequent updates. Google loves fresh content.

health niche, supplements.

In which case, I recommend regular, fresh content.

Neither search engines nor your users care about the number of words in your articles.

Always write for the user, forget SEO in that regard!

SEO content reads like SEO content and everyone knows what that sounds/reads like. Write to the target audience, just as if they were in the room having a cup of coffee with you.

But one needs organic traffic for affiliate income, and readers too. Do long-form articles perform better in SERPs?

Look at your best performing pages and see whether it has primarily long or short articles. Really, the number of words has no meaning, it is not worth counting the words.

If there was a winning format, every site would use it. There is no winning format. It depends on how your visitors engage, return and refer others. If that is not happening, a defined number of words per article will not make it happen.

yes, you are right. :)

Content length matters but that doesn't mean you start focusing on Length.
It depends how well your readers are enjoying your content. To do this you have to

Research on your niches

Research your keywords

Structure of your content

Relevant images

Good Readability

Proper Keyword Distribution, and many more..

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You write as many words as necessary to fulfill the intent of the article/page. No more, no less.

On the other hand, take into consideration the attention spam of your likely users, their literacy level, or their engagement with your topic.

Rocket scientists have one level of interest.

Rock 'n' Rollers have a different level of interest.

Either requires a different approach in language and complexity.