What would it take for euro to dethrone king US dollar?

A key driver behind the euro’s creation was to act as a counterweight to the dollar,

This is false. The reason for the Euro was to make trade easier between EU countries, and to have a more stable currency than countries could provide individually. stable currency and stable economy are tied, and fundamental for economic growth.
It was an extension of decades of cooperation since the 70's between the national banks of EU (EEC) to stabilize European currencies against each other.
https://en.wikipedia.org/wiki/Snake_in_the_tunnel
The Euro is also part of the free movement policy of EU, and a crucial part of the open market, making it easier to trade across borders as individuals too.
https://european-union.europa.eu/institutions-law-budget/euro/history-and-purpose_en

Seems to me the USD has been slowly dethroning itself for a couple of decades now.
To be a good reserve currency requires stability, and USA started the financial crisis in 2008, and is now starting their very own recession.
The USD is already not as almighty as it used to be. But the Euro isn't quick to take over either.
International reserve currency is already somewhat fragmented, and we will probably see more fragmentation between Yuan, Euro and USD. With USD losing ground and the others gaining.

The world already has several global reserve currencies, the euro already being #2. I see no benefit in vying for first place here. I find the whole concept a little artificial anyhow; but hey, I'm not a banker.

Tariffs and trade wars are bad enough. But there are signs he’s willing to go even further and weaponise the dollar to get what he wants. In an off-the-cuff remark during a White House press point last month, he told reporters that the €34 trillion in outstanding US debt would be “looked at” because some of it might be “fraudulent.”

“Toying with the idea of not paying back holders of US debt is a more fundamental threat to the dollar than the end of Bretton Woods.”

Fuck me, this clown is going to create a world-wide recession and dethrone the dollar himself.

trump

Add a Blockchained version of Euro and it's done