BTW, build it with the assumption that it will get soaked in disgusting things. Drywall isn't strong and isn't really washable. Non-stick coatings are best; metal is OK.
There is also a conspicuous consumption aspect that someone who has a washing machine anywhere but the basement is wealthy and care free enough to do substantial repair work, because there's only two kinds of washing machines, the ones that will flood and ruin everything underneath them, or those that already have. Putting a washer on the 3rd floor by the bedroom seems very practical and convenient until the first expensive flood. Of course the trend to fancy up basements means a leak will cause $10K of damage and mold where ever the washer is located, so may as well located it conveniently.
The downside is just noise when running the washing machine.
I would like a house with the laundry on the 2nd near the bedrooms. But I'd make sure it has a spill basin and drain for the inevitable massive leak.