Henryk,
This should be an easy victory for Democrats, but they are on track to lose for the reasons you describe.
Biden's mistake was running. However, that aside, he made Donald Trump the centerpiece of his campaign (the reason he was running) and, in effect, elevated Trump.
Biden either failed to reverse or followed Trump's bad policies internationally with Afghanistan, Iran, TPP, and arguably China and Israel.
Biden has continued Trump's isolationism and protectionism. He multiplied Trump's efforts regarding tariffs and successfully conceded an election advantage of saving American households thousands of dollars annually.
Folk will vote for Trump because an exciting and forward alternative was never presented. And for
a fantastic showman over an old lackluster.
Best to you.