You can't justify it Maud but I think it is useful/important to try to understand it. Middle class workers of America have been eviscerated for about 50 years. GDP has continued to grow in real terms, i.e. correcting for inflation, while wages have stayed essentially flat in real terms. What that means is that pretty much 100 % of the increase in capital over the last 50 years has gone to the owners of capital while virtually none has gone to the providers of labour. That has been a massive transfer of wealth from the middle to the top. Trump promised he would correct that. Obviously he didn't but those who believed in him still do. They blame the "establishment". Trump was seen as not part of the establishment while Biden very much is. They thought Trump would reverse the trend. They think that the establishment stopped him. They are wrong but that doesn't stop them believing it and they are very, very angry.
In reality it doesn't really matter who they elect. America is not ruled by Congress and the White House it is ruled by a collection of interest groups. The most influential are the large investment banks as they own and control the Federal Reserve Banks. After them is the military-industrial complex followed by big pharma. They effectively determine the laws, write the laws and see which laws get passed. You could put a chimpanzee in the White House and it wouldn't make any difference. I guess the last 4 years pretty much prove that idea.
The same thing has been happening in the UK and Europe but with a little mitigation through social intervention. Over my lifetime there has been many changes of government in the UK, mainly Conservative, a significant amount of Labour and a small amount of coalition. Over my time in Greece the government has oscillated between PASOK and New Democracy with a period of Syriza. The changes have not really affected my life to any significant degree. I cannot point to any time in my life when I could say my life was better/worse because Party A/Party B was in power.