The opinions of Biden seem to be all over the map, which is weird since he is the incumbent, and we all ought to know where he stands. There are lots of people (like you) who see the progressive things he has managed to get accomplished, even with a divided Congress in these past two years. Yet, there are others who perceive him as a right-of-center false choice.
He has always had trouble defining himself, which I think is part of the reason he was a perennial Presidential Primary loser. His stutter didn’t help matters, nor his tendency to go off-script. But Trump’s ascendancy gave him the perfect opportunity to create a definition, even if that definition is “Not Trump”.