Most fancy lingerie (or anything with lace) must be washed by hand in a sink. It just makes sense to wash clothes in the washroom as opposed to the kitchen or bathroom, especially since the plumbing is already there for the washing machine.

To store old paint brushes, paint tins and bottles of turps under.

Also if it’s close enough to access via your outdoor entertaining. Fill it with ice to store drinks when you’ve got people over

My mom used it to bathe the pets and to pre wash outdoor clothes that had gotten all mud covered and junk

Mostly cleaning things you dont want to clean where you make your food or disposing of liquids you dont want near your food.

Soaking clothing in bleach, soaking kids clothes...

You can however buy some much nicer looking sinks, benchtops and cabinets that give you the same utility and piss off the big ugly tin cabinet.

In America we call these slop sinks and use them to wash up after getting dirty outside, fixing the car, etc. Or to clean stuff thats too big or messy to use the kitchen sink but in a more controlled way than with a garden hose. As such they tend to be in the little room between the garage and the rest of the house. Sometimes in the basement instead.

Also used to wash certain clothes that are hand-wash only.

The design is different than the picture - deeper and usually fiberglass or plastic.

Well it's useful to clean big things, like the BBQ grill (doesn't fit in kitchen sink), also blankets and things. I honestly never used one until I had a kid and most things you can do in a laundry sink, you can do in a bath.

What if you find a bunch of ducklings covered in crude oil and need to wash them?

Fits a bucket for mopping.

I don't !== Nobody

I mean, my SIL’s place has a European laundry and they intentionally have a deep porcelain basin in the bathroom that doubles as a trough for when they need to do soaks etc.

and nobody washes clothes with their hand anymore.

What ? Replace it if you want of course but that statements false. . We do for example, as well as washing mop heads etc etc

It's also super useful in apartmets that have limited access for washing mud etc off stuff outdoors and washing small dogs.

Thanks guys . I have decided to remove this and install a porcelain wash basin.

I use ours for the litter boxes, scrubbing indoor bins...you know, scullery stuff.