I suggest that you might broaden your news sources. Fox News is not a reliable source. The US economy under Biden is much better than it was under Trump. Trump got very little done, and he reduced the influence and standing of the US internationally, sucked up to and encouraged autocrats such as Putin, and de-stabilised the World's attempts to combat climate change. Biden has stood up to Russia and China. Trump would surrender to them. If Trump regains power, Ukraine and Taiwan, two free countries, will fall to tyranny.
Well informed people in Europe regard Trump as a dangerous threat to democracy in America, and to Global security. Biden has his faults but he has a good team and is seen in Europe as the candidate best placed to lead the democratic World through the next four years. Biden has used his skills as a negotiator to put through bipartisan legislation for the benefit of ordinary Americans. He adopts a multi-lateral approach to international relations, in which a strong America works together with the other democracies to oppose autocracies.
Trump is a convicted felon, on the basis of cogent evidence placed before a jury, and the other criminal charges against him are well supported by evidence. On 6th January 2021, Trump tried to subvert democracy and remain in power in defiance of the Constitution. Trump belongs in jail, not in the White House.
Biden is old, but of the two candidates there is more evidence that Trump, only three years younger and in poor physical health, is cognitively impaired.
RFK Junior is a crank - a supporter of conspiracy theories who is personally responsible for the deaths of children through pushing anti-vax nonsense.