why do people hack?

Some may do it to harm others, some may do it for entertain for themselves, others may do it as practice? haha! idk.

Someone using hacks to destroy game for other peoples.

I usually cheat because i get bored and want to annoy people or because the game is annoying me and i want to get everything(very inpatient)

to make people mad and or because they are bad at the game

Because they're bad, and they can't face feeling like they're helplessly bad...
Maybe even they're hacking because someone else hacked and made them loose ranks or hurt their K/D or Win/Loss ratio in a way that's irreparable... And they feel that either the only way to get back up is by hacking, or by hacking just to get revenge against people who hacked against them...
I find this especially true in competitive games like Fortnite, PUBG, Counter-Strike: Global Offensive and Overwatch..

Especially when you have really sub-par AntiCheat systems like VAC....
There's so many holes that would be so easy to fix... But for some reason Valve is not putting a ton of effort into VAC, or at least it seems...

Because the human mind is very competitive, humans will do anything to be better then others.
Even if it means throwing away game licenses, or ruining the fun of others.

People sometimes hack to feel like they are incharge of the game no one else is.

Most people would say hackers hack in games because they're shit in them. For some people that might be the thing, but from my perspective, a lot of us hack because it's fun and it's really just a whole new game. You might say hacking requires zero skill, but wow, when I first got into it it surprised me to see how the game changed and all the new possibilities.

i only hack games where yiy have to wait to get further because i dont wait 10 years
i made a private server for clash of clans just to try out what will happen wheen you get to the end and trying out what to do and speed up the gameplay

Its kind of fun. It is an unfair advantage from the game perspective but its kindof fun to do and watch the other players stare in disbelief