We can't really gauge how closer btc is to being mainstream. Though we think that more people are now aware of it, we're still not yet reaching the 5% of the population. And with that then it's safe to assume that it is very far from being mainstream. I think this is due to the fact that even people heard of btc they have no idea how it works. Mostly (if not all), tech inclined people are the ones who have the more understanding and have the initiatives to study cryptocurrency. There are more people who tends to steer away from things they don't understand simply because they don't want complications especially if they are busy working on their day jobs.