Genuine question: how much credibility should then people give to Trump's "I inherited this mess from Biden..."?
Pretty much none..except maybe the deficit, but republicans don't exactly deserve a pass on that, either. I mean, just listen to Trump talk. Any "good" news is because of him; any "bad" news is because of Biden. He's a grifter.
The tragedy is that of all the developed countries, the USA had the most growth and lowest inflation under Biden - if anything his administration did pretty darn well, but they just couldn't communicate it or it wasn't good enough to voters. Because monetary inflation tends to take time to work its way through the economy, the COVID pumping and cheques sent out under Trump could arguably be more to blame than anything Biden did (this is arguable either way at this point, though - it takes a lot of time to sift through and understand all the economic data).
Trump has no basic understanding of economics. Unless you want to hoard dollars to sit and do nothing with, you cannot have a trade surplus with every country in the world - and the deficit is only in goods. The USA has service surpluses with most of the world and investment dollars are still coming back into the USA. Trade deficits in durable goods are actually a symptom of wealth.