I'm not sure where you are located or what your intent is but in the US there are barter laws and laws governing the taxation of transactions for the expressed purpose of business, even if they do not use fiat. I'm not a lawyer but I've been around crypto for a while, and I've read through a lot of federal law on this topic.
Most people tend to think that the government wants us to use their fiat and anyone using anything else as a means of transferring wealth, or value, as a business is illegal. This isn't true at all. Trading as a business is completely legitimate but transactions that involve profit, even from trades, are to be taxed.
Ok, so let's now assume you want to start a barter business. Sure, you may not haggle with your customers but if you are trading items, instead of currency for a product, it is a barter business. You, as the business owner now have to record every transaction and reasonably discern the fair market value of everything you trade. At the end of the year, you have to take those numbers and use them as the basis for your income.
Ah, but can't you "cheat" the government by undercutting your estimations of what you trade? Nope! If you run a barter business, and each year the government sees that you make "nothing" or only a couple thousand dollars a year, you will get audited. The auditor will then look at what you do and if it looks at all shady, he will hit-you-hard. Boom, you will owe back-taxes and you could possibly, even face jail time.
In the end, you might have the option to barter/trade for all of your transactions but you can not do this legally and keep your income off the grid as to avoid taxes and the potential of being audited. If you want to do it legally, you will find that managing such a business is such a huge headache that... it will be easier to deal in fiat.
The government isn't so interested in controlling your money-- they just want to be sure that it's tracked so they can skim what they feel is their "fair share". Oh, and when that fair share is due, they choose the medium of payment which is, obviously, fiat. You can barter in tokens and silver all that you want, but come April 15th, you better finds some way to get enough fiat to cover your taxes. Otherwise, you are breaking the law.