but apparently nobody wanted SD cards so they dropped them from all the devices.
I think you have that the wrong way around. It is not that nobody wanted SD cards, but that phone manufacturers realised limiting storage capacity while making continually thinner devices (up to a point) would increasingly drive cyclical demand. "Is your phone getting full after a year or two? Well this one has MORE storage and look how slim and sexy it is by comparison!" It is not as though there was an organic consumer demand for phones without memory cards; the profit-motive drives these changes.
Your analogy is looking a bit leggy at this point.