Let's discuss the potential effects of stable coins which are bound to usd or eur. We usually use them to avoid the volatility or short bitcoin in a way. There are many stable coins in the last year. By writing threat, I didn't mean issues like tether's issue. I mean, they are not coins, they are just usd and eur.
I don't think that these stable coins is a threat to Bitcoin. They have the deflationary tendency just like USD and EUR that is where Bitcoin is proven superior. Any advantage of Bitcoin against inflationary currency will be the same advantage it will have to all stable currency pegged to USD oe EUR.
What if we use bitcoin without these backup stable coins? We may need to learn that we can do without these stable coins, we don't need usd or eur or other traditional money. We should start using directly bitcoin rather than its usd value. For example, an apple may cost some satoshi not cents. Apple's cost depends the traditional way, demand and supply and its price can change in return for satoshis. We should remove usd eur and others, stable or not.
We already use Bitcoin as it is, items are priced in Bitcoin with equivalent of USD price of the item, or usd converted to Bitcoin amount. We cannot remove this USD, EUR or any fiat currency pricing because it is the known universal unit of price of an item.