I don't even know why Mozilla didn't put encoding options at least under preference, but fortunately this extension is great choice as replacement for that removed feature.

I love archaic features so much, that I'm even using splitted reload and stop buttons, panorama tabs, additional toolbars and also spaces and separators.

Works well, but you need to make it visible in add-on settings.

Firefox 109, it works properly

Cool. It works. UI is very nice.
But why Mozilla delete the default character encoding tool?