Dedollarisation is not going to make USD disappear or the trading pairs to vanish. Dedollarisation means different countries are no longer forced to only use this fiat with unlimited supply from an artificial country with almost $32 trillion debt that is printing it non-stop and exports the resulting inflation to those countries.
The real dedollarisation means reduction of dependence on dollar, that consequently reduces USD strength and US power to dictate policies in those countries while strengthening the economy and independence of those countries. So countries that were using USD for 90%-100% of their everything (reseve currency and trading medium) will slowly reduce that to 80%, 70%, 50%, 30%,...
For example after dedollarisation when Indonesia wants to trade with Philippines they don't have to do it using dollar anymore. They'll use numerous different ways they used for thousands of years before United States was invented or they were forced to use dollar and dollar alone. But when each of them want to trade with US or its colonies they can still keep using dollar.
Most importantly, this process is not going to finish over night.
Now, my inner 'crypto-wizard' - a quirky chap, I must say, is itching to hypothesize. Imagine a world taking a rain check on the USD overdrive. Could this lead to nations sliding Bitcoin and its crypto-kin into their fiscal mixtape? Might it spark a digital ripple effect, propelling Bitcoin trading duos to outshine their USD counterparts? Could we be talking about a crypto-world order in our tweets and trending hashtags?
But hey, we're in the realm of 5D chess here. The here and now? The USD is king of the hill. Its might may wane as time rolls on, but the thought of it going up in smoke? That's as likely as catching a unicorn prancing in your backyard!