No widespread adoption is exactly what makes it a bad currency.
It makes it a young currency, not a bad one.
Bitcoin is slower than every current electronic payment (credit card, ACH, wire transfers are accepted in seconds vs. 10-60 minutes for bitcoin)
I can broadcast a bitcoin or a credit card transaction instantly. After 10-60 minutes, I can no longer reverse a bitcoin transaction, whereas I can reverse a credit card transactin for up to 180 days depending on the provider. The recipient can spend the bitcoin instantly without waiting for a confirmation if they choose, whereas it will take several days for the credit card company to pay them the fiat they are owed.
lower fees is a big nope for credit card and ACH.
Credit card transactions cost 2-3% in fees, which could be hundreds or dollars. Bitcoin transactions cost a few cents.
People using bitcoin for actual commerce are the vast minority of people involved in bitcoin. Glad you find use in it as a currency. I'm not expecting that to go mainstream any time soon.
And yet, if nobody used it as a currency then it would have zero value and nobody would be speculating on the price. Using it as a currency drives adoption, and adoption drives price increases.