>use cases are so niche

This is a first-world misperception. There is half a world excluded from traditional payment methods.

Is Bitcoin a realistic option for those people?

Maybe for low-fee international money orders. Certainly not for everyday transactions away from the internet.

Not yet. Five years I'd guess.

That's actually not true. One of the reasons price is high is because people right now are hoarding.

The reward for block discovery also halved quite recently from 50 bitcoins to 25 bitcoins.