If you have enough knowledge about cryptocurrency then go for it. Accepting Bitcoin for business is really profitable as people want to pay without any hassle. Bitcoin is fast and secure as a payment method and it is also easy to handle for sellers also. But it is highly recommend to think about legality of Bitcoin in your country. Otherwise you can face some difficulties in your business.

What others do is convert their bitcoin immediately or on a daily basis to their own fiat, but most others just leave it and start holding it until they need it, whether it's a loss or a profit. They are okay with it. Though money is really essential to the business as you need to buy your product again to restock, so you need to convert it immediately if you don't want to lose money or if you don't want to gain profit from its volatility.

It is a bit hard to give a general answer here without having more information about your business. What kind of products are you selling on Facebook/your own website and are selling only online or also in stores? In my opinion any online store should accept bitcoins these days to be more attractive for the consumers. Also if you are selling products globally you are probably involved in foreign currencies involved that also have a high volatility compared to your base fiat currency. Bitcoins would be a good alternative to all the other currencies that customers could pay in. It really depends on how your sales usually look like and in how many different currencies you deal. There are a few ways you could deal with the risk of losing money in bitcoins or other fiat currencies. The first one would be to exchange all the money back to your own fiat currency each week, like this you reduce the risk of making a loss on your sales. Another option would be if you have suppliers that you need to pay that you could pay them directly in bitcoins. Like that you would only move the bitcoins around and also don't have a lot of risks.

this was a problem of the past. As what others have said here this can only be a major problem to you if you have a business with a static price advert that needs to remain that way to the length of your business. But most online enterprises nowadays, especially ones that use cryptocurrencies as a payment method sees businesses going under the rug over bitcoin/cryptocurrency"s high volatility rate, and so they impose certain programs and parameters that automatically update depending on bitcoin's value, sometimes even real-time. So if you are looking to set up a business but is afraid of the implications that the high volatility of bitcoin may incur, I would suggest you look into these applications as well.

https://github.com/topics/crypto-price-tracker
This one is a good application you can use and implement on your online shopping mart.

Doesn't make sense for a business to take crypto if they're just converting it into stablecoins the moment they receive it. If it's a small business, the fees these payment processers charge them will take up some portion of revenue. And I would never recommend people use stablecoins. You're better off using your local currency if all you're going to do is convert the crypto into another currency.

Obviously there are businesses that take crypto and immediately convert it. But they're usually larger corporations that find it profitable to take in business for crypto users and will eat the cost of the conversion fees. A smaller business doesn't have a chance.

Bitcoin will be profitable for businesses because bitcoin is not a stable currency so the business will improve with the increase in value of bitcoin. Bitcoin is the digital cryptocurrency that has become extremely profitable for both beginners and professionals. Many people are making trading money from bitcoin because of the trading volume available. This automatically creates exciting possibilities for traders with the ability to make quick decisions and reap the benefits quickly at any time.

Here's what I can tell from my experience. I started a rice business and started accepting payments in crypto. Not only in BTC but in all kind of crypto and stable coins which are reputable on the market. I was doing great.
First thing to keep in mind that, if you ever choose to move on physical business rather than online business, you need to have a fast transaction method available.
Accept whatever your customer is choosing for the payment. BTC, BUSD, USDT, BNB, TRX and so on. You can convert them to BTC later and keep holding for the future. You may need some extra for conversion fee, so charge accordingly. This will give your customers freedom and options to choose from. It will increase the user for sure.
Second is the money management. You need to make a plan on how you are going to expand your business with this money and also keep some for the future hodling. So be sure to hodl some and withdraw what you need to keep your business running.

Store them in a safe place so that you won't lose them.

Hope this will help. This is from my personal experience. And one last thing. If there's any legal issue coming from the government, then stop immediately. Don't risk it.

It is a good idea but another question might arise again, does Facebook accept bitcoin as a payment option when you want to create ads? Because the last time when I tried creating a Facebook page for a friend when it was clicking the payment option, I didn't see bitcoin has a payment option. I saw only USD, EURO and NAIRA from my country's end. If you want to accept BTC in your business then you don't have to look the volatility of BTC  because that the nature of it. So as business person it is you will know how to manage the situation at hand.

If you want to add BTC in your social media pages, you can manually state in there even though it is not in app or the site for people or viewers to know that you also accept BTC.

Facebook is an American company and there are only 2 countries (El Salvador and the Central African Republic) so far that lawfully accept bitcoin as a legal tender so we may not see a bitcoin payment setting on these big social media giants. OP can easily mention it in its posts though.

Some business establishments convert bitcoin payments into fiat right away to avoid its volatility. But personally, if I am the one owning the business and it is still small, I will HODL bitcoin payments and only convert it at least in 2025 or after the halving year.