Oh, we're fully in agreement. I'm not arguing in favor of abandoning Firefox or Mozilla at all. I'm just saying frustration and anxiety are to be expected sometimes. Note that I'm not excusing rudeness or the like.
Re: the burden of developing a modern browser, I wonder what librewolf evangelists think would happen to the project, if Firefox development by Mozilla were to fall due to any reason. To my view, the forks only exist because Firefox still does. After all, if managing an entire browser was possible with their resources, they wouldn't need to fork one.