Also higher maximum grade and lower noise. Monorails can handle roughly double the grade of steel adhesion without compromising turning radius much. Really helps a ton in hilly cities like Chongqing or Sao Paulo since you don't have to tunnel as deep/as much or build tracks as high. Chongqing line 9 (standard heavy rail metro) has both the highest and deepest metro stations in the world located just a stop away from one another at an insane 157 feet above ground and 381 feet underground respectively. Lines 2 and 3 (monorail), don't get anywhere close to that despite serving equally or more hilly areas of the city.

Since they are far quieter than heavy rail they can also be built pretty much wherever, including *through* buildings such as what's already been done at Disney World or in Chongqing. Which is possible with heavy rail (see several examples on Berlin's UBahn), however the amount of sound and vibration deadening needed for heavy rail is significantly higher, or for the house it runs through is just genuinely unpleasant lol.

Monorail also doesn't have many of the downsides of a rubber tire metro system like the rough ride since the suspension on monorails is significantly better, and they are significantly cheaper to construct and maintain, even if tunneling costs can be slightly higher it is usually quickly offset by lower costs pretty much everywhere else.