Many democracies have failed. Strong institutions help prevent this, but there has been erosion in U.S. institutions. For example, the peaceful transfer of power after an election. You might want to take your head out the sand and look around. Trump is clearly a student of history (with Mussolini as an idol). George Santayana wrote: "Those who cannot remember the past are condemned to repeat it."

Institutions are only as strong as the people within. We should celebrate those brave enough to stand up to threats of violence and keep their oaths of office, and condemn the cowards who threaten violence and abandon their oaths. Pence kept his oath of office even after a violent mob threatened him.

US added to list of ‘backsliding’ democracies for first time
"The United States is a high-performing democracy, and even improved its performance in indicators of impartial administration (corruption and predictable enforcement) in 2020. However, the declines in civil liberties and checks on government indicate that there are serious problems with the fundamentals of democracy... A historic turning point came in 2020-21 when former president Donald Trump questioned the legitimacy of the 2020 election results in the United States." In addition, Hudson pointed to a "decline in the quality of freedom of association and assembly during the summer of protests in 2020" after the police killing of George Floyd.
theguardian.com - US list backsliding democracies civil liberties international