Warning! Spoilers ahead for Iron Cat #1
It's no secret in the Marvel Universe that Tony Stark has many different Iron Man suits. But it turns out, he actually builds them to keep himself busy and stay away from drinking.
Tony Stark's struggles with alcohol and addiction are notorious within Marvel Comics. In the now-iconic 1979 storyline "Demon in a Bottle," he came to terms with his alcoholism and has been sober ever since. His sobriety has come up every once in awhile, such as when the Scarlet Witch disassembled the Avengers and used her chaos magic to make Tony drunk. He also briefly fell off the wagon during the Superior Iron Man storyline, when his morality center was reversed and he became an evil version of himself.
For the most part, Tony is fairly private when it comes to his sobriety and his up and down battles with alcoholism. But fans get a bit of an insight into his mindset in Iron Cat #1 by Jed MacKay and Pere Perez. This story centers around Black Cat and the Iron Cat suit that Tony Stark had made for her. An updated version of the original suit is stolen by Black Cat's childhood rival. When she questions Stark about the upgrades, he says that he did it to keep his hands busy, which prevents him from growing bored and craving a drink.
Boredom is a common cause of relapses for alcoholics, which is why people struggling with addiction are often advised to try and keep themselves busy. So it's not surprising that somebody like Tony Stark, who is a tinkerer by nature, constantly works on and upgrades his old suits. He's also known for having a large assortment of backup suits, each tailored for different situations and purposes. A lot of times this is associated with the fact that Tony Stark is a planner and likes to be ready for every contingency, but looking at his fleet of suits through the perspective of his alcoholism provides some new insights into his character.
Although Tony's constant tinkering is good for his sobriety, it might prove troublesome for his friends. If he was doing something as mundane as working on a car it wouldn't be such a big issue. But the Iron Man armor is a weapon. So if he's constantly working on new suits just for the sake of staying busy, that means he's essentially creating new and different weapons that might be abused. Black Cat can testify to this firsthand as the updated Iron Cat suit is stolen and she is attacked by it. Still, having extra Iron Man armors lying around is better than Tony Stark relapsing.