Even after I hit level 10, I still made GAs, because I had a lot of keys that I had no use for, and it removed some malus, which gave me more chance of winning more challenges.
I think the most I won in a day was three, and at that point I could only win the archer killing, and only if RNG meant a lot spawned where I happened to be standing.
Now things have changed with the challenges. You only get malus if you win a key, and while I won eight keys last month, I've only won one key this month. The suspicious activity hits more often than getting a key, sometimes it even happens on the first challenge.
So there's no real reason to make GAs now, and I'm getting fewer keys, and the ones I do get I mostly use on SG groups to build value ratio to win things I don't have.