This, of course, has never been true.

"The elections of 1800 and 1824 were so convoluted they had to be resolved by 'contingent elections' held in the House … As a result, the winner in each race … wasn’t determined until February of the following year." https://www.nytimes.com/2020/05/18/opinion/2020-election-results-delay.html

"The election of 1876 took even longer because of irregularities in the returns of several states. A congressional election commission … finally awarded the presidency to Rutherford B. Hayes in early March" https://www.nytimes.com/2020/05/18/opinion/2020-election-results-delay.html

"Several famously close races — in 1948, 1960 and 2004, for instance — weren’t decided until a day after Election Day. Most notably, the contested election of 2000 stretched into mid-December before the Supreme Court, in Bush v. Gore, cemented Florida’s vote certification…"