This is what the supporters of limping technologies always say: "it's only been seriously considered for the last year or two, so it's too early to consider the results". And yet clearly, it has not been just 2 years over which we've considered blockchains. Why are blockchains more credible than all the other failed technologies for which these kinds of arguments are made?

Whatever problems you may have with international bank transfers, they work: every business in the world relies on them. For all the supposed benefits of blockchains, no blockchain solution can make that claim, or any claim close to it.