Trump taking claim for the economy is a bit like Obama hitting a 300 yard drive, then, while the ball is still in the air, Trump bends down & retrieves the tee, then takes credit for the drive.
It's also just normal politics. Most people believe that the president has a big impact on the economy, good or bad, trend or no trend. Generally speaking that's not true regardless of which president you're talking about. Most of the growth or decline that comes within a presidents' 4 year term comes from stuff that came before he entered office, and the influence they can have overall is very incremental, even if they have the full 8 year term.
The only real exception to that is when there's an economic shock and the conditions exist for a dramatic intervention in the economy. The decisions they make to respond to that are more influential, but they are also largely dictated by the nature of the shock. Trump can take credit for the record Q3 growth and it is clearly true that he favoured re-opening the economy over the well-being of the nation, so you would expect that added a little bit on top vs. a more cautious approach that would have been taken by Biden. But irrespective of who was in charge, there was going to massive growth. Likewise for past economic crises.
That doesn't make intuitive sense to the average voter because that's not how people talk about the presidents' economic impact. So it's entirely normal Trump would profit off of that in the way basically every president in the same scenario has in the past. And there have been many on both sides.
There was a discussion few pages back about what motivates Trump voters, especially minority voters. Obviously many different factors, and it looked like people were focusing on (as with 2016) racist whites and (new) bigoted Latinos.
One of the big ones that I forgot about, that no pollster checked, and that was totally silent from both campaigns: the CARES act $1200, signed by Donald J Trump, and the $600/week increase in unemployment benefits that came after it.
US poverty rate was at its lowest for decades for a short 3-month period after the $1200 and while the unemployment was enhanced, and lower-wealth people could show savings for basically the first time ever. Neither party talked about it too much, and neither campaign pushed messaging about expanding or continuing the cash. So the only name associated with it was the one in the signature.
On a side note, Pelosi was asked about negotiations for extending this stimulus and let slip in the interview that she didn't want to do it because "Trump just wanted to give people money' while she wanted additional things (mask mandates and stuff like that). Now, I don't know if anyone outside like 5 twitter leftists have even bothered seeing the interview, I didn't catch it in any media outlet, but if anyone did see it I think they woul much prefer Trump over his opposition.
Those additional things also included state and local aid which would be necessary to provide essential services for local communities, in fairness. A little abstract for the average voter but it's not like she was holding out for things that were totally irrelevant to the average person, or reliant on them sharing the same view about how to tackle the pandemic. Most people don't want their local government to go bankrupt.
She didn't approve further direct economic aid because she was playing political games in two ways: she wanted more stuff that fits with her political goals, and she didn't want to give Trump the popularity boost from putting money directly into people's pockets just as the election came in. The former seems like bad political calculus but the latter seems like it might have been necessary to get Biden into office. It absolutely would have been a win for Trump and if he only needs a few thousand people in a few states to win the election now, then it's entirely plausible to believe it could have swung it. Which in the long run you can justify as being in the interest of the people you've fecked over, because when there's a democratic president they'll get a larger stimulus plan through. Disgusting part of politics though, and also could be another critical misjudgment from Democrats in believing that they can get it through the senate. I reckon her political games are a big part of the reason for losing some of the house.