Couple of ways. First it’s got to be able to scale, SegWit is helping clear the mempool so people aren’t waiting hours or even days at its worst for confirmed transactions. It’s got to be easy to use. People don’t care what protocol a website uses to serve content, whether it’s TCP or UDP, they just want it to work. It’s got to be secure, so people don’t lose money by sending BTC to a BCH address, the wallets have to stop people from making those mistakes.
It’s got to be able to interact with the currencies that we have now, outside of centralized exchanges. Hodlhodl.com is a great example of progress on that front. Additional technical upgrades like MAST to allow for more applications other than just a store of value. Price fluctuations are another thing, I think I commented to Dlew12 about this but eventually the price should somewhat stabilize. Those are ways it will get broader adoption.