Every MMT denier's argument is always the same...it will fail, someday. When is that someday and why? I never see a detailed explanation to support this claim. The reasoning is always based on two tenants - 1. this is what economist have said as long as they could remember. 2. They're scared foreign debt holders will get nervous.
Most of these same people felt it was completely reasonable for the government to 'stimulate' the economy during the pandemic but during other times it was doom and gloom with a side of inflation. The payments paid to citizens as part of pandemic relief has appeared to have a net positive effect on the economy, despite the people who have been screaming inflation the past year.
I want, better yet, challenge someone to provide a well thought out counter to MMT on where its been tried, how it was implemented and failed. I'm not incredibly pro MMT but I find most arguments against it seriously lacking, would love to digest a serious opposing opinion.