I remember the article from 2016 titled “Hamburger Menus and Hidden Navigation Hurt UX Metrics” where the conclusion from NN/g was:

Discoverability is cut almost in half by hiding a website’s main navigation. Also, task time is longer and perceived task difficulty increases.

Fast forward nearly 10 years later and NN/g says:

Hamburger menus are a more familiar pattern today than 10 years ago, but the same old best practices for hidden navigation still apply.

Kate Kaplan, revisiting her conclusion from nearly a decade ago:

Over the past decade, the hamburger menu — much like its namesake — has become a classic. As mobile-first design took hold, it offered a clean, space-saving solution, and when design leaders like Apple and Amazon adopted it, others followed. Its growing ubiquity helped standardize its meaning: Through repeated exposure, users learned to recognize and interpret the icon with increasing confidence.

I think the hamburger menu grew in popularity despite NN/g’s authoritative finger wagging. As designers, most of the time, we have to balance between the needs of the project and client with known best practices. Many websites, especially e-commerce, don’t have four or fewer main navigation links. We had to put the links somewhere and the hamburger menu made sense.