I have very few issues with Firefox. I fine across a site that does not render properly maybe once every other month. I did have some resource issues with it in Windows 10 with it using too much RAM (regularly using 3-4GB) but that has been fixed since I switch to Linux.
Lmao love how you inserted "software engineer" there like that supposed to mean something.
In this context, maybe it kinda does. We tend to be techies, so a bit more accustomed to shitty UI/UX than most users.