Making a product purchase with cryptocurrency is problematic. And without process changes, cryptocurrency will never replace fiat currency.
People are speculating with crypto, not using it to buy products and services. New York-based blockchain researcher Chainalysis Inc. research shows that only 1.3% of economic transactions came from merchants in the first four months of 2019. This percentage is little changed over the prior two years.
Cryptocurrency systemic problems will keep crypto in the speculative realm. Problems include:
Crypto price volatility - Who would use crypto to pay their monthly wireless bill with a digital coin that could surge 50% in a matter of weeks? Furthermore, sellers and buyers have difficulty establishing "fair" prices. Product prices do not remain current when the underlying currency prices change frequently.
Crypto transaction processing times - The time to process a purchase payment is way too long. A case in point is when I bought a product online the other day that took almost 10 minutes to clear. This delayed the product delivery process start time until payment confirmation occurred. The vendor website told me to submit a support ticket if payment was not confirmed within 15 hours. What?!
High transaction fees - Crypto transactions include a user fee. The fee increases during periods of high crypto demand.
Trust Issues - Slow transaction processing and crypto scams may limit people's trust. Lack of trust may further delay transactional use cryptocurrency.
A 2018 report by the Bank for International Settlements discusses the limitations of cryptocurrency replacing conventional money. https://www.bis.org/publ/arpdf/ar2018e5.htm
If given a choice between using a credit card or cryptocurrency to make a purchase, I will choose a credit card first. But this is not to say I won't refuse any crypto sent my way. I will stash it in my digital piggy bank.