Why are people betting YES?

Definitely!!!

According to Wikipedia (Nov 2022), there are only six accounts with >100 million followers: Barack Obama, Elon Musk, Justin, Bieber, Katy Perry, Rihanna, and Christiano Ronaldo.
The base rate for accounts having that many followers is extremely low.

Will an AI have >100 million Twitter followers this decade?, 8k, beautiful, illustration, trending on art station, picture of the day, epic composition