My new job gave me an iPhone 7. I have no complaints per se about the hardware, but I dislike iOS compared to Android - far less flexible and intuitive. I honestly have no idea how Apple became so popular.
I am in the same camp as you, although I think that from an industrial design perspective Android flagships are far superior to iPhones (non X).
As for how Apple became popular? A few reasons. Early on Android wasn't very good. The original iPhone was really well done for the time - competing Android phones were simply not, and the OEMs weren't exactly super well known (look up the HTC Dream, for example...). Samsung did not launch the Galaxy lineup until 2009 IIRC.
It took until Android 4.4 or so for the ecosystem to really solidify, I think.
The second reason is that Apple is incredibly good at marketing and has created a cult-effect around their products. The iPod was already a hit, so they had momentum behind them already. The iPhone has become a "standard fare luxury item", the "default phone" in essence, that everyone wants. Have you ever noticed how most iPhone cases proudly have a cutout for the Apple logo?
I don't really see myself ever going back to iOS (I had a 3GS briefly, it was pretty decent for the time) for my personal phone but they do hand them out for work. Whatever. Then again I am a guy who is sitting at his kitchen island in his underwear with no less than three Lenovo Thinkpads on the countertop so I am definitely not the target market.
I miss my Motorola RAZR the most.