Lets assume bitcoin has a larger community and the oldest blockchain,and never prepared for such a large population, so which might have struggled for this reason. What can we say for those that opted for coin for online payment even for their online shopping mall like SGGCOIN, INS that never succeeded? Another factor for bitcoin medium of payment is its volatility. Tether should be an option of payment with its stable value, I hope it can be adopted.
Without question,
extreme price volatility makes a currency undesirable as a medium of exchange (MoE). At times
BTC has been more stable than the USD. Of course, there have been times of extreme price volatility.
The best tactic to allow a cryptocurrency to be used as a MoE is to design it such that a buyer and/or a seller can quickly convert from fiat or to fiat currency in moments such that there is no exposure to price volatility.
Consider if at time of purchase the buyer can upload from their bank account or credit card a sum of fiat currency and the wallet immediate converts this into this cryptocurrency, and then transfers this cryptocurrency to the seller's point of sale system, where the POS system converts the cryptocurrency into a fiat currency (let's a different currency than the one the buyer loaded into the wallet). This sequence could happen in a span of a few seconds.