why do people hack?

Hacking is a like minigame inside of a game, It is fun to try and avoid anti cheats and try to out smart another cheater. I would call cheating a new gamemode for games, it is a great way to learn how to program and some times cheating can be used to uncover bugs and exploits that could otherwise be exploited for money.
I suggest you to watch this video on youtube to see what my and some of other people's perspective on cheating is: https://www.youtube.com/watch?v=gniSF1M9g_o

hacks can bring another view of fun to the game if used sensibly

They don't want to hustle harder and always get a shortcut. cursed.

To feel superior or just annoy other players is my guess.

Therere a lot of reasons tbh. To get cool stuff the easier way, to annoy others, or just because theyre bored *shrugs*

I would say that they like the feeling of "being good". However i've seen a lot of hackers in csgo who use for example wallhacks and still can't kill people most of the times because their aim is bad.

Because I get bored in games and it's fun to try and not get caught. !

Some genuine reasons, such as helping companies avoid being hacked. Who better to combat hacking than a hacker?

Personal reasons. I had a family experience recently that was a little scary regarding my mum and her recently divorced husband. Certain hacking abilities would have been very handy. Especially as the police said they could do nothing.

Likely the main reason is that it's got the whole voyeurism aspect to it. I can see you, you can't see me king of thing. Like being a spy... while sitting in bed eating chips!

because they can and have too much time in their plate, i guess..

could be for any reason really. Boredom, fun, for financial gain.