you've clearly never tried to mash a large quantity of potatoes with a fork.

it's the same reason people like pasta rollers even though a rolling pin will technically get the job done. 2 hours or sweating and panting as you roll with all your might will get you to understand real quick.

You can also cut bread with a silverware knife but it's not as easy or fast

If you don't need it but like once a year or once every few years, sure a fork will work. It's a pain but doable.

It's the reason I don't own a mortar and pestle. The few times I do need something like that, I just use two bowls or spoons or whatever I have on hand. It sucks but it's once in a while so it's not worth precious cabinet space.

Why would you need a floor brush for brushing something so specific?

Wouldn't a toothbrush do?