There are cheaters in the game yeah, but it isn't as bad as people make it to be. People keep callings cheats on anyone that's just better than them...half the time it's just LEMs smurfing in Nova territory.
The big issue right now with CS is the shitty planting, jumping and ladder hitboxes. Valve did confirm they are aware of it and are working on it...though how far a fix is is up in the air...'cause volvo.
Also, some shots that should have hit that do not will keep happening as long as official MM is running 64 ticks...'till then if you can't take it, go play CEVO, FaceIt, or shell a few bucks for ESEA.
And that is full of it-- Betting and gambling doesn't affect the game's gameplay whatsoever-- just do like a crapload of people do: ignore it if you don't care about it. CS:GO is the first CS game that gets any form of support from Valve (which admittedly is still not enough, but still...progress).
I only recent started playing CS:GO, it's a lot of fun. This whole "it's a s**t pile going downhill" is just an exaggeration. If you don't get all buttthurt about winning 100% of the time and being too serious, the game is still wonderful. I 5 man queue with people in the AK or Eagle level (as Nova 4), and we just have fun, there are matches where we are serious and matches where we just mess around till we lose or we somehow win. Stop taking the game too seriously and enjoy it.
As with the hitboxes and "netcode" issues, that's a problem that Valve is working on, or said to be working one. Netcode issues won't really change unless you are on a 128 tick server or have zero ping and zero packet loss, as shots may or may not register on server that register on your screen, one of the Hawaii guys has this issue a lot due to his location. And hitboxes are just a thing, why it's like that I can't say, but it is.
Plus, cheaters give you a lot of satisfaction when you kick their butts cause they suck so bad or get VAC banned on the spot. We had an aim bot on the opposing team that carried them through the first half and he got VAC banned on the spot. Lost the match but it sure was funny.
It's not as bad as you might think. Valve has done a lot as far as introducing anti-cheat measures into the game. There are still only a few types of cheats that go undetected by VAC. The new updates to OW have been great too, along with the fact that you have to be rank 3 to play competitive now.