Is MMR in ranked a fair system?

Hi there, I haven't been playing ranked all TOO much recently, a few games here and there, but I've been playing since 2010 and personally believe I've gotten to be quite decent at the game, to the point where I fair up in lane against players at my current MMR, which is low platinum, while I am currently at Silver 1, Gold 5 last season, and while I understand that players with MMR higher than their existing rank get more LP per win and lose less per loss, I can't help but wonder how the system can be considered fair, if someone like myself in silver can be paired up against platinum players, is the rank really a good representation of a player's skill, wouldn't it make more sense for a player to only be able to match against people within their own league or division? If this were the case, silver players would only play other silver players, golds playing other golds and things of the like, and the rank would likely be more representative of the actual skill or flexibility of the player, as they would be climbing through games with players actually representative of that rank.

I could be entirely wrong, and I'm willing to accept that I might be, but as it stands I can't see any real reason as to how I would be.