You think Trump was the winner by a landslide? Then how come his approval rating was so low in the first place. He was never popular to begin with.
Trump was more popular in 306 electorates compared to Hillary Clinton in 232 electorates (38 of the electorates Trump won were in Texas, 29 in Florida, and 20 in Pennsylvania, 87 electoral votes in just three states, over a quarter of the electoral votes in just three states).
If Clinton were to win those 87 votes, then she would have been POTUS, with no Joe Biden as president unless Clinton were to lose the primaries.
The most rural states in the US are Vermont, Maine, West Virginia, Mississippi, and Montana.
Vermont had 3 electoral votes for Hillary Clinton, Maine had 4 electoral votes for Clinton, West Virginia had 5 electoral votes for Trump, Mississippi had 6 electoral votes for Trump, and Montana had 3 electoral votes for Trump.
In the 5 most rural states of America, Trump had 14 electoral votes compared to 7 for Hillary Clinton.
Whereas the most urban states in the US are DC, California, Nevada, New Jersey, and Florida.
All those states except Florida had more electoral votes for Clinton over Trump, totalling at 78 for Clinton compared to 29 for Trump.
Either way, with those number of electoral votes in these states, not all of the electoral votes for those states went one way, they were however projected for the specified candidate as a majority.
https://www.bbc.com/news/election/us2016/results
https://worldpopulationreview.com/state-rankings/most-rural-states
https://www.visualcapitalist.com/sp/mapping-us-urbanization-by-state/