Hasn't 2048 always been free? When comparing a paid game with a clone that's free (or even "free-to-play with obnoxious ads and lootbox mechanics" not that 2048 is that) the latter will usually become more popular, and that certainly happened here.
I am not sure how I feel about it. I certainly don't believe anyone should be able to legally own an idea like "sliding tile number games based on powers of 2 with or without being multiplied by 3" but I also don't have a lot of respect for those who, lacking an original idea, resort to cloning someone else's creative work (or in 2048's case, I guess, cloning another clone). So I guess I have no problem with them existing, but don't feel any desire to give them accolades or to play their game.