You neglect the number one issue for why people voted for Biden - because he wasn't Trump - and they saw that as by far the biggest issue due to the danger he presented to this country. That didn't mean they didn't also care about other issues, but by and large Biden voters approved of his policies as well. Trump also tried to overturn all of Obama's policies including Obamacare, even though a majority approved of it. The majority of American's also approved of the policies Biden overturned, so you may think it's his policies that are driving his poll numbers down but up until Afghanistan, he still was above 50% approval. He deserves the criticism he got for that disastrous exit but let's not get ahead of ourselves and blame it on anything else, just because you don't like his policies. Me thinks you're mis-reading the tea leaves.