> I needed to understand why our checkout had to be improved; I explained that technology choices made no difference to the user. However, the manager interpret

> I needed to understand why our checkout had to be improved; I explained that technology choices made no difference to the user. However, the manager interpreted my words as outright rejecting their idea. Let's be honest, that's what happened here. There are many reasons to overhaul a frontend, and performance is just one of them. Maybe the existing checkout is a mess that only OP understands how to maintain. Maybe engineers and designers want to find better common ground to work together and this change could facilitate that. I'm sure you can think of other reasons. The narrow thinking is on OPs side here. They straight up assumed that this change was just chasing shiny new things (and, well, React isn't that shiny anymore), that all changes had to serve the user and not also organizational goals and then shut it down with the nearest plausible excuse.