With 50% signal you can't make a phone call because the device lies about the real signal level. You see, when the device has no signal, people will blame the device, if the device lies that it has signal, the people will blame the network (because the calls fails). And there are many more issues like this. I still feel robed that I bought an iphone (the best there was) and I wish people would have warned me about it.
There's reason iphone is no 1 in us an nowere else: it has to do will limited access to education, so simpler devices are "best". In the rest of the world is about social signalling: I can afford it. If you had access to good education and you don't care about social signalling then there is no point in buying one as there are much better devices with android. Even my ten year old samsung has more features than the iphone.