I'm a master. It was a hard slog to get there. There are definitely cheating Masters and Grannies. I've reported them, and they've been banned for it. But not everyone at that level cheats.
As pointed out above. going for second, while dickish and resembles cheating, gets you points. I don't do it often, but it is effective.
I'm currently a Master and have achieved the status of Grandmaster for a short time. It is possible to reach these levels without cheating though, so I resent your premise that ALL Masters and Grandmasters are cheaters, but it is definitely a problem. There does need to be an emoji made to alert other players that may be oblivious cheaters while still in the game as it is hard to tell sometimes weather it is just an alliance or collaborators. It is great that they have made some changes to reporting people but that doesnt help you turn the tide while still in the game. SMG has to create an algorithm to block two profiles that consistently in games together, as it is pathetic for people to achieve Master or Grandmaster by doing this and degrades the accomplishments of people that are actually good at the game.
On a separate note, if you would like to get to higher levels stop playing with Novices and Beginners, as losing to these players will severely lower your ranking. Once you achieve a higher ranking status put the filters on that block lower levels, that's how you move up there buddy.
Agree that the vast majority of GrandMasters are cheaters, with a minority just being lame players who only play 1 on 1 + bots games so they can have an online rank to feel good about when they having no other successes in life. However, I have achieved Grand Master ranking several times, so it certainly possible to do it without cheating or being totally lame. May be impossible to stay there for long, however, because there is so much cheating out there. I would say that I see cheating in about 15-20% of the games I play. Usually, as soon as I identify the top account in the cheater group, I just try to take them out as punishment, since 1 v 2 is an impossible proposition.