I currently am a Supreme Master First Class, the 2nd highest ranking in MM from the top and once you get near this level you will find at least 1 person in your match is hacking almost every single time.
At lower ranks this is not an issue which is why I have a couple of accounts I keep at a low rank to play with friends so I don't have to worry as much about getting wall hacked. As far as ESEA and AltPug go, their servers are considerably better, all 128 Tick while MM is only 64 Tick.
The anti-cheat in ESEA and AltPug are also a lot better then VAC and Overwatch so the amount of hackers will be greatly reduced, keeping the playing field more fair. However the skill level of those who play in ESEA are going to be a lot better then those in MM, so if you want to get good fast and learn some tricks and tips by watching great players then I would spend the money for ESEA. Altpug is free and newer but I still enjoy the quality of their servers and the skill level of people is more similar to match making.