My belief is that Bitcoin is a store of wealth, and is not suitable for everyday retail transactions. However, services such as the lightning network can allow Bitcoin to be used in a retail environment, but the Bitcoin itself is still a deposited asset, rather than a currency.
We need to remember that during the early days, even precious metals like Gold were used as a currency and a trading unit rather than using it as a store of value. During these days, currencies were minted out of gold and silver rather than steel (well, probably a non-worthy metal). As days progressed by, the mining cost of gold increased along with rarity and price. Today they have been considered as a investment option rather than a currency.
Similarly bitcoin was created to be used as a currency similar to euros and USD. Most importantly, the primary factor against the usage of bitcoin as a currency is the extreme inflation rates governing them. A volatile material can not be effectively used in retail day to day transactions. Gold and other precious metals does have inflation rates but on a lower percentage when compared to btc. Even the mass adoption will rather increase the volatility in the market which might be a bad sign for its usage as a currency. But we people believe that once all the 21 million has been mined, the volatility might get reduced to an extent.
On top of that, a guy doesnt need to have knowledge on Bitcoin to use it i beleive. With the development of payment portals for cryptocurrencies, it has become easy for one to use btc similar to Visa payment process or other credit and debit card systems. On the other hand, the merchant needs to understand the basics of using cryptocurrencies. Just mentioning a label "Bitcoin Accepted Here!" alone doesnt help him in successfully receiving them as a payment. As ETFBitcoin said, coins present in bc1 addresses can be sent only to segwit supported wallets . The merchant either should integrate his wallet with an exchange and it must immediately convert btc to fiat/Tether to prevent his losses with inflation prices or must be well aware with cryptocurrency techs etc.
However, services such as the lightning network can allow Bitcoin to be used in a retail environment, but the Bitcoin itself is still a deposited asset, rather than a currency.
Lightning Network just increases the scalability and increases the speed of transactions. Each and every time the sender and receiver should pay to open a channel which might be a little cumbersome and would not go well for all.