I often think that Trump ran in 2016 to publicize "Trump TV" (remember that?). He never really expected to go as far as he did, certainly not win the presidency. And once he did, he didn't have a clue of what to do.
The episode is in contrast to other Black Mirror episodes with its contemporary setting; it explores public distrust of politicians. Initially based in part on the politician and future British prime minister Boris Johnson, the character of Waldo was widely compared to business magnate Donald Trump following his successful 2016 campaign to become President of the United States.
Trump had his moment and the politicians sucked and people were sick and tired of the status quo.