Do smartphone Android charger cords lose their effectiveness over time?

To put it bluntly, USB cables do wear out, regardless of the device's operating system. And that's because they're supposed to.

The basic USB Type A jack you have on a PC is rated for 1,500 plug/unplug cycles. That means that, after about 1,500 plugs and unplug, something is likely to be about worn out. No plug or jack lasts forever, and when USB was invented, no one was expecting to be plugging and unplugging every day.

When the USB Organization introduced the Micro-B and then Type-C connectors, it was assumed that lots of plugging and unplugging would occur. All of these sort of connectors have a set of contacts in the plug and a set of contacts in the jack. One of those sets will have contact springs, in order to ensure a positive contact between plug and jack. One of the innovations of Micro-B and Type-C was to locate the contact springs in the plug, not the jack.

So over time, your cable is supposed to wear out… rather than your device. The device should last about 10,000 plug-unplug cycles. The cable can be pretty long lived, too, but in practice, it's quite possible to put additional strain on a USB cable while in use, shortening the cable life. But not that of your phone or other device. And all legal USB cables and devices have to conform to these specifications. That is the big advantage of an industry standard over arbitrary proprietary solutions.