Election processes expressed as cars.

In the leadup to Joe Biden’s withdrawal from the US presidential race there has been huge debate about the various shortfalls of both Biden and Donald Trump, but to me the big question is how did these two candidates ever get selected in the first place?  I can only put it down to the US electoral system  which to me stifles innovation and maximizes nepotism and corruption, and its lack of proportional representation means that there is no possibility of alternative political parties coming to the fore.  Many people call it the greatest democracy on earth but compared to proportional representation democracy it seems like an old model T Ford, good in its time but long  overdue for a complete redesign.