The problem is Trump is so much more vastly worse than Biden who else could do better? You have most conservatives who will never vote for anyone other than Trump. The real question is how well informed are the independents, and if they are watching media, what are they watching. If it's FOX, then they are not informed to make a sound decision.
Would another Obama type have better numbers? No matter who it is for the democrats there will be poorly informed voters who won;t like that person. Most who dislike Biden do so on wrong beliefs, like the economy being bad, or that he is anti-Israel, or anti-Gaza. Or that he's too old. He is old, but looking at his public performances he's vastly more stable and sharp than Trump. So the reason the polls are what they are is due to too many poorly informed voters, and poor judgment.
Let's note that Biden was behind in the polls in 2020. Trump was behind in the polls in 2016. Obama was behind in the polls in 2012. There's no reason to pay attention to poll numbers five months before the election.
I agree that polls don't always tell the whole story, and as you say, it's still five months away from the election. At this point, my prediction is that Trump will likely lose the election. But the issues revolving around Trump and the general movement of America Firsters will continue to fester. Trump is not going to last forever, but what is the plan for after Trump?
I don't really know how well or poorly informed other voters might be. I think most citizens are probably just focused on their own lives and their day-to-day existence, while politics may be more of an abstraction to them. Even if they watch the news and become aware of the political issues, they may still see it as something far away. I'm quite certain that even the most poorly informed voters were probably told by someone at some point that Trump was a horrible person. It's not that they don't know all these things about Trump, but they simply don't care.
I don't think they're a bunch of confused, ignorant people who just aren't getting the right information. It's more a matter of raw, outright defiance. I won't necessarily compare it to the Southern hotheads in the Civil War era, but I can see some shades of similarity. I even see it in non-political situations, where people might be inclined to take a defiant, unyielding "screw you" attitude more often than not. There's a certain brazenness about it, along with raw anger and hatred. It seems a strange mix of paleo-conservative American mythos combined with pop culture nihilism.
One example which goes back a number of years is that, while I was posting on the IMDb message boards, I noticed there were certain groups of posters who would tend to root for the villains in movies - or characters who were otherwise odious or awful. Like Joe Pesci's characters in Goodfellas and Casino. Or Travis Bickle in Taxi Driver, Ajax in The Warriors, the Cobra Kai in The Karate Kid, etc. Another example might be Al Pacino as both Michael Corleone and Tony Montana (Scarface). I remember one guy telling me that he admired the character of Michael Corleone because "he didn't take any crap from anyone."
Another movie from the 1990s was Falling Down with Michael Douglas, and I noticed that this movie has been getting some renewed attention lately, as there have been some recent reviews on YouTube I came across which ties the imagery of the movie with current events and considers it even more relevant than it might have been when it first came out.
Maybe this isn't the way people are supposed to think, but I've observed that this kind of thinking has somehow permeated into some of the darker corners and recesses of Americana. And it may not have much to do with politics directly, but it's just further indication of the underlying nihilistic defiance which seems to be out there. I'm not saying the movies are the issue either, but it's often interesting to see how people react to certain stimuli.
So, I honestly don't see it as a matter of certain voters being poorly informed or duped by propaganda. That may very well be true in a lot of cases, but it's only because they don't want to hear what they don't want to hear. Not to mention there have always been a certain percentage of Americans who tend to take a "screw you" attitude towards government and authority in general, from both ends of the political spectrum and even across class lines as well.
If there's one silver lining in all of this, if Trump does manage to win, he'll probably screw things up so badly that things will get even worse for the average American, and Trump's support base could quickly wither away. The very flower of right-wing politics will then be revealed to them, and they may end up moving all the way over to the far left. We could have AOC in 2028.