Well you can't tell if it's the "elites" they usually have streamer mode like any normal person would do it avoid being annoyed in match which means their names are randomized. So no way to tell. Also the only time in this game I call hacks is 1.) Was I 100-0 in .2 seconds and if this is true then when I spectate do I see him doing the same? I've taken down 6 enemies in probably less than 15 seconds before (which means I quite literally blew their heads off right away) So it's not always hacks.
Although there definitely is a major problem with hackers currently they are EXTREMELY easy to see. Also not sure what your talking about on CSGO if you play competitive CSGO you do NOT get a 5-10 second replay of the last kill. What your talking about is casual CSGO which doesn't mean much and is hardly a good way to gauge anything. I've played competitive FPS shooters since I was about 12-13 starting with CS 1.6 and played Cal-I on 1.6 mostly for scrims as I was young at that time. Cal-i was invite only (pro scene). Most times if people are just tracing you and landing shots it's probably not a hack. As when they aimbot you'll quite literally just almost instantly disappear. Also when your strafing are you weaving with using crouch as well or literally just moving side to side? Cause that won't really affect anyones aim who is half way decent.
I guess most times when I see these posts I should ask if your level 100+? Your rank? Hour count in game? Only cause I've seen people cry hacks and they weren't even max level yet so their game experience is almost non existent. Not saying everyone who hasn't put in the hours can't tell if someones hacking but I'd take someones word whos got 1k hours+ over someone who hasn't even capped yet.
The main things that help identify a hacker is going to be the overall TTK (time to kill) and often times MOVEMENT. A lot of hackers are COMPLETE garbage at the game because obviously they have no reason to be good when they can just auto-aim everywhere. You'll see them loot boxes while standing completely still, they don't holster weapons, they don't slide jump for increased speed, cross hair placement is complete garbage (auto aims so doesnt matter) but just something to notice. Also just spectate and record, I don't have the link on hand but you can send in video evidence to them and within 1-2 days (business days) they'll have the account banned if it's provable beyond reasonable doubt.
The only hack I've noticed so far that's super hard to notice is the soft hack where two (I'm assuming bots) have no armor but quite literally almost never take damage and pretty much down everyone and the last guy (who does have armor and takes damage) will finish them off so you end up spec'ing him over the dummy accounts and don't see anything suspicious. This one is just hard to pin down except the tell-tale of 2 teammates with no shields at 10 minutes into the game and them never taking damage lol. But when you send it in for a report it can't really prove anything because it's always spectating the guy doing nothing in terms of hacking. I'm sure Respawn once they figure this one out they can actually switch the POV to the other 2 squad mates though. I added this last part just to make everyone aware of this one because most people don't even notice or pay any attention to this.