To be more precise, there will be a short term spike in inflation in 2021 and 2022, it will be short term precisely because the source of the excessive demand will also result in more supply over the long term and therefore prices will fall over the long term again averaging to less than 2% inflation. If the inflation rate ends up staying up over the long term then the Fed gets to play the hero, which is something it was waiting for since 2008 and perhaps since the dotcom bubble.