Escobar's immense wealth became problematic when he couldn't launder his cash quick enough.
He resorted to stashing piles of cash in Colombian farming fields, dilapidated warehouses, and in the walls of cartel members' homes, according to Roberto Escobar, the cartel's chief accountant and the kingpin's brother, in his book, "The Accountant's Story: Inside the violent world of the Medellín cartel."
"Pablo was earning so much that each year we would write off 10% of the money because the rats would eat it in storage or it would be damaged by water or lost," Escobar wrote.
That would be about $2.1 billion, given how much money he was reportedly making.
Escobar simply had more money than he knew to do with, and therefore haphazardly losing money to rodents and mold wasn't an issue.
Source: The Accountant's Story: Inside the violent world of the Medellín cartel