This incident should serve as a very good lesson to those in the Firefox community who often claim that memory and performance problems don't exist, even after numerous users report experiencing such problems.

Such memory and CPU consumption problems are often blamed on vague "third-party extensions", even when they happen with fresh installations on systems that have never before had Firefox installed. Or they're otherwise blamed on the user somehow, even when the user is engaging in a perfectly reasonable workflow.

And even if the problems don't happen on one system, they very well could be happening on another system, as this very incident shows quite well.

This part of the article is particularly relevant: "Shortly after that, while on a plane I tried pdf.js on my Mac laptop. I was horrified to find that memory usage was much higher than on the Linux desktop machine on which I had done my optimizations. The first document I measured made Firefox’s RSS (resident set size, a.k.a. physical memory usage) peak at over 1,000 MiB. The corresponding number on my Linux desktop had been 400 MiB!"

This matches very well with what so many Firefox users describe as happening to them. The memory consumption ends up skyrocketing to well above what it reasonably should be. Gigabytes of memory are unjustifiably consumed.

Perhaps now instead of ridiculing or ignoring people who report such issues, those in the Firefox community will perhaps do the responsible thing and take them seriously. It should be very obvious now that memory consumption problems can happen on one system, while not happening on another.