Since he came in to office:
- started bombing middle east again.
- played identity politics.
- approves of transitioning children.
- border crisis.
- closed the Keystone XL pipeline - which is bad for everyone including the environment.
- talks about increasing taxes.
And he still has a 54% approval rate.
Could be that their sample is likely voters or the general population. In either case, it would include non-voters. They might be more inclined to favor Biden.