Some things to consider:

There are stablecoins that could become mainstream methods of payment for goods. That covers the volatility issue.

As more governments issue national digital currencies, the distribution of funds such as stimulus checks and tax returns will be blockchain-based.

As more and more traditional financial institutions get into the crypto game, they will incorporate the blockchain tech into their existing transaction systems, so it's very possible that the majority of people will begin using crypto without even knowing it. Think about it, how many people actually understand how credit card transactions actually work?