democracy has never done that historically

It absolutely has, Scandinavian countries are good examples of democracy actually working. They rank highest on the democracy index, and they also rank highest in satisfaction in the population and quality of living, and quality of public services.
The better the democracy, the better the results.
Problem is that USA is an awfully bad democracy, and for half a century nothing has been done to improve it. Not even making gerrymandering illegal, or remove the idiotic FPP voting for federal elections. Which are so obvious and a bare minimum to move forward.

For now our democracy here in Denmark where I live is working very well, but that is not an automatic thing, it is something we need to continuously protect, and in general Europeans are better at that than Americans.
We (EU) have the same problems USA do, like AfD in Germany and Le Penn in France, the difference is that here those extremists although popular, cannot take total power of the system, because in functioning democracies you have representation of many parties, and no government is allowed almost total power like the US president has.

The US system with a very powerful president is based on an idea of efficiency to get things done, not an idea of democracy and fairness like most European democracies.
Don't judge democracy based on the flawed democracies that exist, democracy is the least bad system we have, but a flawed democracies like USA and UK, are doomed to make HUGE mistakes in the name of efficiency, because too much power is concentrated with 1 person. Except when it comes to it, they are only efficient at maintaining the status quo of the power structure, and never really getting much done to benefit society as a whole.