Hacking is pretty bad in this game. I have seen it A LOT. in fact anymore I have made it my mission to report every hacker I find and I have found A LOT. I know what to look for. I am not proud of it. But, I have hacked in games before. But, not Apex legends....atleast not yet. But, it's so bad you almost have to hack just enjoy yourself anymore.
But, basically the easiest way to spot it is by seeing there aimbot. It is impossible to follow someone's every move. So, if you are spectating someone and there cross hairs are litterally always on target....more than likely a hacker. For reference I hacked back in Counter-strike 1.3...or maybe it was 1.6. I did it because I was bored with the game. I had played since 7.1 and the game was tired by then. But, the hacks I had for CS could be programmed to target different zones in the body. So, you could set it to focus on someones HEAD with tight tolerences...which is obvious. You will almost always get banned/kick for that. Or you could set it to someones body with loose tolerences. This allows your crosshairs to shake a little bit. It simulates a natural aim. But, basically if you are spectating someone and there crosshairs are always in about the same point on the body even when the target is jumping back and forth...then yea it's like 99 percent a hack. Also, they will snap to targets. That is one of the other things I look for. If you have a player and there shooting at one person and there cross hairs auto switch to another target more than likely a hack. See the hack I used back in CS 1.6 could be turn on and off with a button. So you could run around with it off and then you see a target and you push the button and instaskill. But, while you have the button pushed it will snap to which ever target is closest to the crosshairs. So you will see hackers focus one target and when another target gets close there cross hairs will snap to the other target.
Of course this isn't the only way to hack. If you have a wall hack you can see everyone. So, players that are always running to a location of an enemy I suspect of wall hacking. But, it is difficult to catch people doing that. In CS you would have people do it because there was a lot of stuff you could shoot through. But, in this game not a lot of stuff can be shot through. But, I have spotted a number of people with SUPERHUMAN(more than likely hacks) Grenade placement.
I personally do not like hacking. I think this game would be a great game if the hacking was brought down to a minimum. I do not think you will ever get rid of it completely. But, yea right now I would say it's an easy 40 percent of the population. I hit a hacker almost every single run. If it was like 5 percent it would be more tolerable. But, the game has so much potential without hacking. Because, with hacking shootouts are so pointless. But, with out hacking you can Dodge and duck and slide. But, against a hacker all those moves are pointless because there aimbot just follows you everywhere. Which is why I do not hack games unless I'm bored with it, because it makes the game pointless. I only did it in CS because I was bored with it. But, hacks make the game pointless. Because you can literally push a button and become a GOD in the game and you do not need any skill. With the right hacks you can push one button and run around in circles and still win. So, it stops being fun IMO with hacks. But there are so many people doing it that I have thought about downloading some skill just to compete.