The details require a little knowledge of Dota, but essentially the bot only knows how to play a much simplified version of the game. They play with a reduced

The details require a little knowledge of Dota, but essentially the bot only knows how to play a much simplified version of the game. They play with a reduced number of playable heroes (5 of the 100+). Each hero changes the dynamic of the game and many heroes have unique interactions with each other, so this is a very substantial simplification. Additionally, Dota is a game where mechanics (the ability to quickly and precisely click the thing you intend to click) play a huge role and bots have a natural advantage there. Another important skill in Dota is watching everything that's going on, positioning your screen in the right place and paying attention to the minimap. As bots don't interact with the game via a screen (I believe the game exposes variables that describe the full state of the game that the bots can see), this is another advantage they have.