Bidenomics is

Trump was the one who delayed shutting down the country due to anti-vax and anti-covid stance. Then we had to shutdown longer and has to print money for people causing crazy inflation for years.

By what metric is the economy not doing better under Biden?

Inflation has nothing to do with presidents. Unless your president doesn’t close the country fast to avoid the pandemic from spreading and then has to print money to give handouts to businesses and citizens. Then it affects inflation. Biden can’t do shit to stop it. Trump couldn’t avoid printing money. People were dying and suffering. Businesses were hurting. The money HAD to be printed. Then post Covid there was supply shortage due to worldwide shutdowns and wars. This caused more inflation. Low supply means more expensive products. More printed money means less value per dollar. These are economics basics. However if we would’ve shut down the country earlier this would’ve prevented the pandemic from spreading like wildfire and we could’ve bounced back earlier without having to give handouts. That would’ve atleast saved the money printing inflation. It’s easy to say Biden or Trump caused inflation but you have to look at the details like an engineer to understand how it happened and why.