there are two problems that i see preventing or at least slowing down such adoption.
first is the very small adoption of bitcoin itself. so far not that many people know about bitcoin and from those people a small percentage have actually bought bitcoin. and finally from that small percentage, even a small percentage are also willing to spend their bitcoins as they would any other currency and instead prefer holding it as an investment.
so when the demand for the grocery store to accept bitcoin is very little to non-existent in some places, we can't expect them to start accepting bitcoin.
second problem is the fees. not just them being high from time to time (although that is also a downside) but them going up during spikes. it creates bad experience. imagine paying with the recommended fee then suddenly there is a spike and your fee is no longer high enough. it has happened to me multiple times and at most i had to bump the fee 3 times to get it to confirm after making a trade. and that turns people away and that little percentage i mentioned above also joins the other percentage in holding as an investment instead.
That's certainly true, mate. Despite Bitcoin's rise in price on the market, it still lacks mainstream adoption. I guess this is largely attributed to price volatility, slow transaction processing times, and high fees. Merchants and businesses alike might never use Bitcoin as a serious currency for daily commerce other than as a store of value. The pioneer cryptocurrency is more suitable as a long-term investment than anything else. Of course, we already have the Lightning Network which aims to make Bitcoin payments instant and dirt cheap. But the learning curve is quite steep, preventing everyday people from using it in the mainstream world (I've often found the LN confusing when I first started using it). As long as the aforementioned issues are present in Bitcoin, merchants and businesses will continue to use traditional Fiat for daily payments.
Nonetheless, we already have stablecoins which aim to provide the "best of both worlds". My guess is that Bitcoin will continue to be used as a sort of "hedge" against Fiat, while stablecoins will be used for daily commerce. Bitcoin will be the new digital Gold that will be used alongside Fiat for many generations. It's already useful as a censorship-resistant cryptocurrency that's impervious to third-party intervention. People who value this, will choose Bitcoin above anything else. Others who want convenience will simply choose stablecoins. While it'll be nice to buy food or groceries with Bitcoin someday, it's certainly not a priority right now. With the use of crypto payment processors/gateways, we can get a credit/debit card which serves as a bridge between the world of Fiat and Bitcoin. This is certainly a workaround for buying daily necessities with your hard-earned Bitcoin. Just my thoughts