You're right. The phone changed. When Apple moved to MagSafe charging, the coil in the phone was moved into an optimal location for MagSafe chargers. MagSafe chargers are still Qi Wireless Standard.
Many older chargers have no issues charging the changed iPhone. But many older chargers do. There is no industry standard mandate on where a charging coil should be in a wireless charger. Some manufacturers got it right and their chargers work fine. But for those who put their coil in a spot which is not optimal for iPhone and as Dogcow suggested above Android phones, well those chargers just don't work. And that is not Apple's fault. That is not Androids fault. It is simply a misaligned coil for the newer generation phones.
Technology continues to advance. It will continue to advance and some older devices just aren't up to the job they were designed for a few years ago.
And I just read this:
"MagSafe is truly one of the wonders of the modern world.
It makes wireless charging way better and easier, and it’s great for accessories like car mounts. There’s a range of useful and interesting gewgaws that can be clamped magnetically to the back of your iPhone.
And now it’s coming to Android – and everything else that’s charged wirelessly.
The Wireless Power Consortium says Apple’s MagSafe will be built into the next-generation Qi charging standard, allowing a range of devices to benefit from the magnetic system.
This is a win for everyone, and it’s great to see a good idea like MagSafe get the widest possible distribution throughout the product world by becoming a standard.
Kudos to Apple for letting this happen."
As I said, Technology moves forward and that's that.