@jimwoodswrites The short answer is I have seen this with my work and the work I do for clients. It terms of performance I meant more than just traffic. I meant how much revenue they generate. Longer content, in my experience, generates higher quality email list signups. The people willing to invest the time in a long article tend to be people with high rates of buyer intent, not just tire kickers.
When you have people with higher buyer intent in your sales funnel, you make more money.
However, long posts also give you more SEO chances and give you more opportunities to generate backlinks as there is more content for people to link to.
Neil Patel has a good case study on traffic and 3,000+ word blog posts. https://neilpatel.com/blog/why-you-need-to-create-evergreen-long-form-content-and-how-to-produce-it/
Of course like everything else, your mileage may vary.