I'm not seeing a "mainstream-ization of the crypto currencies". A few years ago, quite a few local businesses were experimenting with accepting cryptocurrency payments, and I could buy all kinds of stuff and services using bitcoin. I could order a pizza with bitcoin, I could buy electronics at a major retailer, I could buy plane tickets, I could pay for lunch in a local cafe.
That's not the case any more, by now all these local companies have stopped accepting bitcoin, because after the first hype, the volume simply was not there to make it worth their while. Some people (often the same people!) bought some stuff initially to try it out, but that was it, there was no sustainable mainstream business. It's still usable for some online services targeting the tech crowd, especially where anonymity might be a feature, but for everyday use of paying for physical goods and in-person services there has been the opposite of "mainstream-ization" in my experience; by now the mainstream businesses have tried crypto and found it not useful. There's enough well developed infrastructure and service providers so that mainstream businesses could easily accept cryptocurrencies if they wanted, but they don't, because there's no significant customer demand outside specific niche markets.