Bitcoin price goes up and down all the time. If someone buys something costing 10$, the next day it may cost less or more. So it's a risk for the seller.
If they are going to be converting it to fiat at the end of the day, then it’s of no need. It would be better for them to just accept fiat and nothing else. And moreover, there is a fee that is being charged when you try converting your coins to fiat or another cryptocurrency.
Cryptocurrency is good, but I won’t recommend it to a small business. A small business that is making use of cryptocurrency might be experiencing loss, because of the processes that will be involved in converting and withdrawing their money. Big businesses are the ones that can accept Bitcoin, because they will still cover up the fees and wouldn’t mind if the price of Bitcoin drops.
But immediately converting it into fiat will make them more vulnerable to the fees, so maybe they will just save or hold it for awhile and they will convert it altogether when its price is reasonable for a profit. Also a business that accepts crypto will really grow from time to time, they just need to comprehend how bitcoin moves in the market so that they know what to do with them. Although a small business will do, but you need to become more flexible and you learn how to adjust for your small business to grow. For a big companies, it is not that hard for them to make profit using cryptocurrency because big companies have business partners and that will make them to promote more and gain cryptocurrency when they know that people are using it as a payment in transactions.