Call them cheaters, not hackers :) They don't hack shit. All they do is buy someone else's work to give their egos a little treat due to not being able to handle losing to better players in a video game. And to answer your question: I don't play CS2 at the moment but I played a few Premier matches to get a rank and already faced cheaters in those... There are barely any cheaters on Faceit. If there are any they will get banned sooner or later. Exceptions always exist but if you want to improve or just dislike playing against cheaters -> choose anything other than Valve servers.
