Stablecoins are crypto assets pegged to the value of Fiat, bringing people the "best of both worlds". The most popular stablecoins are often pegged to the US Dollar, since it's the world's reserve currency. Some of them comply with regulations, further legitimizing the industry as we speak. With all of the benefits stablecoins provide, Fiat's prominence could be threatened in the long run. After all, it's much faster and cheaper to use a stablecoin than a credit/debit card. People could stop using Fiat currencies like the US Dollar or the Euro in exchange for a stablecoin of their choice.
This makes me wonder, will stablecoins replace Fiat currencies in the future? If not, why? Is there a possibility governments will adopt stablecoins as their own instead of launching digital currencies from scratch? Your input will be greatly appreciated. Thanks in advance.

I believe this is an argument that has been on for a while now and I believe you are asking if Crypto will replace Fiat because that is what I see in this post. The very stable Coins you are talking about as you said are pegged to Fiat currency, that is what makes them the stable coin that they are and until the Governments are able to totally control the cryptocurrency ecosystem, I most say that this notion of replacing fiat is not happening because Gold, Silver and Platinum could as well be use for exchange too but did not replace fiat and there is a reason why it will remain so.