Actually right but he was trying to think of a way which can make fluctuations smaller like limiting the maximum drop/rise a day to $500 but obviously we cannot do it because you can't stop buyers from buying and you cannot force sellers into holding. But to solve the same problem stable-coins were made to eliminate these risks and if you are a merchant you might actually want to accept altcoins like TRX because BTC payments will take hours and transaction fees also hurts. I am only suggesting TRX because it has free of cost transactions and quick confirmations and the price for TRX never dropped or jumped too much either.
By the way there are merchants like bitrefill who accept bitcoins payment but how they manage price fluctuations is by constantly updating price of the cart items every 10 mins when you are on the payment page. Like if you had $10 amazon gift card and move to checkout then the price will be fixed for 10-15 mins and then update according to the market price.
Unfortunately TRX is not a good choice for merchants considering it is fast and cheap but at the same time lacks development. This means if you want to accept crypto so that you could have more crypto and profit later on, that would be a bad choice, since it may not go up like the other ones, look at the current situation where everything goes up but Tron fails to go up, whereas if you pick something else you could live with that.
For example if you use Tron blockchain but Tron itself, that would be a lot better for you, such as using USDT but on TRC20 blockchain, that way you will be getting usdt and the price of it will not change and you will still get it fast and cheap, or you could accept something like BNB for example which would be cheap and fast as well and it is not a bad coin (increased as high as third place) so you could always find an alternative.