Straws
Straws are useful but can’t exactly be called a high-tech product. They are a simple aid that helps transfer liquid from a container to our mouths. They shouldn’t be too hard to make. It turns out that it’s hard to make them properly.
They often snap in the middle, which results in spilling the drink all over the place. They are intended for single use, and by default, don’t require high-quality materials. It’s not an excuse, though. They should at least make them good enough to last through that single use.