There were a dota2 bot match events before. Dota2 had a great bots moment like the go, when open ai's dota2 bots beat human players, and showcased different meta strategy of winning the game.

I believe the bot ti was no longer hosted because there seems no strong monetizing channels. Even that a lot of people enjoy them.

[1] https://liquipedia.net/dota2/Bot_TI/2019