I worked on an app for a few years (in the earlier part of this decade), and we redesigned the heck out of the app, moving from tabbar based design to hamburger

I worked on an app for a few years (in the earlier part of this decade), and we redesigned the heck out of the app, moving from tabbar based design to hamburger menu. Literally everyone in the company were super happy about how the app looked. When we did UX testing with real users, and also some users who were given the scenarios, it became painfully obvious about how much of a cognitive load it was, for the users to understand what's hidden behind the hamburger menu. But we still continued with this design, because we (the organization as a while) didn't have the gumption to revert back to tabbar based design while HB menu was still the rage, and a year later Apple mentioned in one of the WWDC talks that Hamburger Menu is not cool. Recently, I quit an app company because (in addition to other reasons) they decided to move from tab to hamburger (and I had an another offer).