I think that this will happen soon, because taking bitcoins by sellers will lead to higher prices for goods because of high fees. For small purchases, this decision will be very unprofitable.
I'm guessing you do not own a business. I only use bitcoin and it has led to lower prices. I expect to pay 1-3% less if I use bitcoin. The businesses I work with have seen huge profits because of bitcoin. The fees on credit card transactions are high compared to bitcoin fees not the other way round. Not to mention the many rules about who you can deal with, what you can buy, where you can shop, the ever-changing contract terms, the penalties, gotcha-fees, the risk to your identity, the 2-180 day wait for clearing the transaction... You get the idea.
Even as we speak?
You are maybe forgetting that receiving bitcoins implies two fees.
The one the customers pays when they buy the product and then when you collect the payment from the multiple addresses used for payments.
For things that are sold under 20$ very merchant will go with the credit card.
As for the rules....you're forgetting that there is one rule . the customer is always right.
So as long as the customer prefers something, the seller will have to bow down.
Of course segwit might solve a few problems but we still have to see it fully implemented and in use.