Washing machines can last from 8 to 20 years but most times you'll be needing to replace the washing machine within 10 years depending on how much you use the washing machine.
I've seen some washing machines advertised on TV that are supposed to last up to 25 years which would be a good lifespan but I doubt any washing machine made today would last 25 years but It could be possible.
My mom had a Maytag washing machine that was 40 years old when she got rid of it for a new washer and dryer set and the 40 year old Maytag washing machine still worked but she just gave it to a guy who's now still using it to wash his overalls etc in his work shop.
I doubt any washing machine made today though would last over 40 years though.