With the amount of time we spend on phones, I think this should be a big issue for us.
Speak for yourself.
I once saved a texting woman from being run over by a train ... and she did not even realize it the mortal danger that she had been in: she continued texting throughout.
Then (which happened before touchscreen smartphones came around) I promised that I would never turn into such an idiot. Now I see lots of such idiots everywhere, people who are not mindful of their surroundings, and downright rude and obnoxious to other people in the real world because they are too absorbed in their phones. Idiocracy has turned into the norm.
Please do not turn into such a person.
With a standard USB-A-to-micro-USB adapter I can plug a keyboard directly into my Galaxy and immediately start typing.
You can also connect pretty much every keyboard to an Apple iPhone, using an adapter.
The downside is that they would draw power from the phone. There are also half-decent Bluetooth keyboards with their own batteries though.