Weight helps for consistency, but it’s also much easier: you just put the bowl or pot on the and toss stuff in. Fewer measuring cups to clean, and you don’t have to wonder how much of the honey (etc) actually made it into the bowl.
You can even retare the scale between ingredients if you don’t want to do mental math.
Yeah. Measuring by volume is a nightmare. 3tbsp of unmelted butter? How am I supposed to measure that? 3tbsp of melted butter? So I just have to guess and then melt too much? A cup of brown sugar? Is it packed? To what extent? And now I have to clean that cup because I need it again for flour?
I've never seen butter in a tub before. We get weird "spreadable" vegetable-based butter substitutes in tubs. Some British people call it margarine but that's incorrect as margarine comes in solid blocks like butter (it's uncommon these days as it's no longer really needed).
In the US we have "whipped butter" which (according to Wikipedia) is made spreadable by aerating it with nitrogen. I recall hearing that it isn't suitable for situations that require measuring because the volume is not the same. (But it does works well on bread or for greasing a pan.)
You can even retare the scale between ingredients if you don’t want to do mental math.