I believe the answer to your question would be when the big supermarkets accept some form of btc for their goods.
In my opinion, people will feel comfortable using BTC if they have enough knowledge on how to use it as currency, an asset and an investment, experience the benefits given by BTC and if it is fully accepted worldwide.
Those who are not feeling comfortable with the Bitcoin can surely stop investment or using the Bitcoin because their insufficient knowledge made them feel uncomfortable and is the main reason. Now as we know about people who were with low wealth are now millionaires and billionaires because they used the Bitcoin correctly. It is a much benefited way and we do not have to waste our times more.