Look at the people around us and how they are using crypto currencies. Most of them are just using it as a store of value instead of a regular currency. Most of them are using it for making profits. They cash out their profits in fiat! How do you expect bitcoin to take down banks when people act in this way.
This happens because as many people said, cryptocurrencies are not accepted widely enough to be used by people frequently for daily uses.
Even I read that cryptocurrency is still banned in some countries. So people have no choice but to exchange it to fiat.
Honestly my experience about sharing bitcoin stuff to rest of the world is pretty lame. I have told every person in my friend circle, including the techy cyber persons and guess what they actually are against it because of the same reasons you taught, it's volatile nature, insecurity and less acceptance in the community.
Let's just agree we can't force someone to like bitcoin.
What's the benefit of using bitcoin that you told them? If it's not really important to them or even they don't need it, then it's useless to try to convince them.