When someone pays with the USD or some other fiat currency, it is always guaranteed that the money you are giving away is going to deteriorate over time, so it's better to purchase something else with it. Paying with Crypto is completely different as its value always goes up.
In a bull market, buying something with Crypto is basically throwing away future money that you are going to get just by holding it. Even buying something inexpensive and cheap stings when you purchase it with Crypto, so people just buy using whatever Fiat they have laying around.
In a bear market or a dip, buying something with Crypto is basically giving up and taking a loss and giving it to someone else at a discount. Crypto investors are supposed to accumulate during dips considering the market has recovered almost every time in the future, and selling Crypto in this period is a no-no.
So what are you supposed to do as a business owner to increase Crypto adoption? the answer is discounts. A lot of businesses are already doing this. Not only are their customers happy with their discounts and are more likely to pay with Crypto, the businesses also get to accumulate Cryptocurrencies. It's a win-win situation.
TLDR: If you want people to pay with Crypto as a business owner, you should offer discounts because people always value Cryptocurrencies much higher than the market price.