Theory is only as good as it is useful and it is as only useful as it is predictive (or explanative). I've have been engage in theory play on a digital cluster model of economic innovation through understanding cross company transactions. Generic projections were in the ball park but still off by the end of 2020 GDP by 3.5% (April 2020 GDP Contracts 1st Q of 2020-Is It a Short Lived Shock and Digital GDP Recovery?) COVID pushed digital transformation forward quickly in turn causing forced adaptation (Nov, 2019 Digital GDP on Government's Mind. Can We Maximize Growth Through Cluster Development?) leaving behind lots of small and medium size businesses (increased bankruptcies) that couldn't adapt quick enough (unable to scale digitally).
GDP was 3.5% lower (lots of reasons but one plausible explanation is from a re-emergences of COVID and lockdowns). 2021 and somewhere around 2023-24 would be big wins for the U.S. economy as adaptation strategies kick in (I'm not the expert but I have a few ideas on post-covid rebound transactional innovative clusters). There were some natural economic changes with COVID that haven't been fully realized as we gain a new level of homeostasis ( March 2020 How the Economy Might Change After COVID-19?)
Managing Director Art Hogan of National Securities Corporation is an expert on market predictions and he believes there is going to be "economic explosions" in 2021. Its helpful to follow market leaders to see if what you believe is in line with what they believe. Sometimes they let you know little bits and pieces of their projection strategies.