I just want to bring to both @Oduda and @Taemien’s attentions that there is a non-neglectable difference between the two cases.
Let’s say you trust a waiter/waitress and give them your credit card to pay for a meal.
→ First, there are safety measures into place to avoid bad scenarios, like a limit for contact-less payment, a secret code being required for other payments, an double-authentification for internet payments, an option for you to block all payments etc. etc.
→ Second, if the waitstaff does abuse your credit card, they are very likely to face severe consequences; for instance, since it is malpractice from them, they would get fired, lose their job, probably also get blacklisted from many places, and they would be considered a criminal which comes with a variety of consequences.
→ Third, if you instantly catch them doing something fishy, they subject themselves to your reaction, which can be violent for instance.
Now we have people playing a game IRL.
→ Depending on the type and format of the game, there are more or less safety measures.
→ If someone cheats, there may or may not be consequences, but usually there aren’t many because a game is mundane. (Exception when it’s high-level competition, usually with money involved)
→ If one gets caught, the reaction can happen and be pretty bad, but usually not too awful because a game is not considered as important as money for most people.
Here more specifically, we have the case of Online Gaming 
→ There are some anti-cheat systems in place in most games, although not all of them are reliable.
→ If someone cheats, the consequences are generally mundane, the worst being a permanent ban which can inflict Emotional Damage to someone who is deeply invested in said game.
→ If one gets caught, the distance and anonymity protects them from others’ reaction being a potential threat, so they get away with it more easily, or even enjoy this type of reaction (a troll basically).
And finally, we have Conan Exiles… 
→ The anti-cheat system is poor, the exploits and cheats are constantly present.
→ If someone cheats, the consequences are extremely low, if the moderation ever makes such consequences happen (on officials at least)
And a permanent ban is easily circumvented by buying a new account for super cheap (or so I heard) 
→ And of course, those cheaters are not subject to the threat of others’ reaction.
TLDR Conclusion Something:
• People keep one another in-check through social interactions and potential threats IRL. They behave overall decently with one another to avoid things going badly for themselves, and consequently, others.
• If people can do something “bad” that benefits them, some will do it as long as there is no punishment, no real consequences for them. This is very often the case online due to distance and anonymity, and even more in gaming.