Every game is vulnerable to hacks and it depends on a lot of factors. One of the biggest is the engine. If people know the engine and it is fairly old then there are more known ways to hack the game.
In addition, most anti-cheat is primarily reactive. New hacks are very possible, but once they are detected they have to build a new one. That is how you can sometimes see hackers still today. New hacks that aren’t detected yet can slip through. One of the big reasons why the in game reporting feature is important is due to these new hacks. The more people who get reported the better.
Hackers will always exist, more for some games than others. It is not impossible to hack any game, you just need to know the engine and have some motivation. Like the old myth that Apple OS couldn’t be hacked is a complete fallacy. It just wasn’t profitable.
In your case you may be just fighting players who have a significant amount of skill. It is possible to feel like highly skilled players are hacking. This is primarily because you aren’t spectating them, seeing what they are seeing or think like they think. Most hackers are quite obvious and will be killing by the scores with relatively few deaths at all.
The reason for more hackusations is relative skill difference. Just because you aren’t able to match their skill doesn’t mean they have an unfair advantage. The next time you think somebody is hacking, try spectating them to see how they perform. You might learn something as well that could improve your own gameplay.
If you believe somebody is hacking it is better to report them and move on. Trying to call them out in the server won’t be effective unless it is quite obvious to everybody involved.
