Most think that the cracks in the financial system started to appear after 2008 (global financial crisis) and become truly visible after the financial system was weaponized through the seizures of Russian central bank USD reserves. It setup a precedent that it happened once it could happen again to some other country.

Cheers to you for mentioning Triffin's dilemma. In my opinion, the dilemma is in the ability of the host country to be able to make "good use" of the exorbitant privilege. The financial system was not only used against other states but against its own people. Instead of developing the country and building equity through the middle class, it cannibalized its own.