Crypto adoption - How much longer until it goes mainstream?

It seems like crypto adoption is still years away, considering the fact many people still neglect to use Apple Pay or other similarly related services involving electronic payments.

I'm beginning to wonder if crypto won't go mainstream until larger financial institutions get more involved with say, btc for example. I imagine a time when traditional electronic brokers such as ETrade, TD Ameritrade, etc figure out a way to offer crypto to their clients. The next best group of people to invest in crypto would be retail investors who already dabble in the stock market. I don't know how critical it is for them to understand the underlying principals behind the blockchain protocol in order to invest (read Herbalife).

Another critical point would be when larger institutions such as Vangaurd allow corporate employees or anyone with a Vanguard 401k to diversify into crypto. That would create a tremendous amount in capital into the markets that has yet to be tapped.

How much longer do you folks think it will take, or will the general public not even be aware of its existence as it works behind the scenes?