It's sometimes good to remember that many people have been debunking several
of Nielsen's assertions about usability for more than two decades. Not least the one about only needing to test with five users.
Here's a good study from 2001 (yes, 23 years ago) about page load times. By Christine Perfetti and Lori Landesman.
Remember when Amazon took 36 seconds to load over a 56kbps modem?
https://web.archive.org/web/20130501084018/http://www.uie.com/events/roadshow/articles/download_time/
#ux #uxdesign
More recent, but still 12 years ago...
https://www.wired.com/2012/04/why-jakob-nielsen-is-wrong-about-mobile-websites/