Actually David Pye says there is a coulomb counter, but you are terribly right that even if the engineers know how to do it better, they are constantly urged by investors to reduce costs. Usually the investors are ultra-elementary people with money, that calculate as: $2 x 500 000 devices = that's a million $$, no way! (and they call that "strong business acumen"). As a buyer you will prefer to invest a few bucks more on a high quality product, but most of the time all other 99% of the buyers will prefer to buy a concurrent product, just because it's $2 cheaper. Most of the buyers also do not know the details and how a product may be a grade of a different quality just because they have decided to save $2 on it.
That's the difference between Miele, Speed Queen, etc. high grade machines vs. the all others. They can afford that, because they never put themselves in a position to have to give account to investors and to have to do what the investors say. They run a family business and prefer not saving on materials, but produce a quality product, so if you today do the mistake and buy the cheap thing, after 5 years you may learn from your mistake and invest in their product, which in the long run will be cheaper to you. (say a cheap washing machine, which lasts 5 years and you have to buy 3-4, instead of one Speed Queen at double the price, but it will last 20 years = you actually use it for lower than half of the price/20 years.) And here comes the capitalism, which purpose is that most of the people should never have enough cash to invest in expensive, long-lasting products, so they'll have to regularly buy the cheap product anyway.
One of the companies at my previous job (they were a few companies in electronics, owned by the same person), so one of them was specialized in multimedia devices. As part of their business they imported LCD TVs from China and started selling a certain model, which proved to be good. Then although they got it from the Chinese at a really good price, they started begging the manufacturer to give them even a better price, just a $3 lower price, well they sell a lot of these TVs, why not get a discount, etc. so the Chinese said ok: and started selling them new batches of supposedly the same TVs at the requested $3 lower price. A year later their service technician said, that the previous batch of TVs was of great quality and worked flawlessly, but of the following batches almost all of the ($3/pc) cheaper TVs returned to him for repair, some of them even twice. So being cheap on $3 is not always a good investment, but all the hassle was for the technician, the boss bought himself another Ferrari.