I can’t speak for the lower ranks, but I was mid-ish on premium this season (played from 17k to 23k then stopped iirc) but a lot of the cheaters were subtle enough that not everyone realized that they were cheating, even though they pretty blatant from my perspective. (For reference, I play lvl 10 faceit and have a decent understanding of the game.)
Point being that a ”subtle hacker” might be subtle to some and obvious to others. So OP, being a newbie with only 6 mo of experience, might suspect someone being subtle about their hacking but they might be very blatant to a more experienced player.
Or, and I'm speaking from my experience in TF2 here... they're just good.
TF2 is an interesting case study because it's a very old game with a very high skill ceiling. I have 2,000 hours now. Players with 4,000 hand my ass to me.
The difference between an aimbot and a sweaty 4,000 hour sniper is close to none. You peak the corner and within 200ms you're dead. It's easy to think they're cheating, then you open up their steam profile and no, they just have even less of a life than me.
They'll even headshot you when you got invisible on spy. Yes, really. They have so much experience their hands have remembered the movement speed and trajectory of spy. So you go invis, and then they can predict where you're going to be and headshot you. Especially so if you go for a health pack or ammo. It's really crazy stuff, but not cheating.
Point being that a ”subtle hacker” might be subtle to some and obvious to others. So OP, being a newbie with only 6 mo of experience, might suspect someone being subtle about their hacking but they might be very blatant to a more experienced player.