That's just not enough games to be considered a streak man. Sorry, but you played some 80 games of ranked so far? Take a look at coin flips. Coin toss simulator Streaks happen like yours even at 50% odds. Lol is very much not a 50% game eather, if your undervalued your team has advantage if your over valued you team has disadvantage, that is the only thing you can expect in every match.
Making it harder does not prevent smurfing, it would keep smurfs into that elo longer. Division Skips are what riot does to deal with smurfs, not punishing winstreaks.... and even 8 games is not a streak. Remember its elo system we are talking about an expectation that it takes 100's of games for that system to come online for fairly accurate judgment of assigned skill to player true skill.
To rig matches you have to assume that riot has a system that can judge player strength even with a small sample size of games, and predict from previous matches if they are tilted or a high % odds to lose a game. Theres 0 way for it to tell If they will 1st time randomly or troll after a first death. It has to track a high number of variables for every game to create a Badness will throw games odds%.
Not only that but those bad players will have to be given win streaks as well to balance out the loss streaks, now for them to win, it has to be off their teammates carrying them because they are trash who lose games when placed with players of a similar MMR to them. Oh.. riot doesn't rig wins, just losses? They only and actively punish players for doing well, to make the climb harder? Again... 100's of matches for elo system, not only that, there's 0 reason for them to do this as its a very complicated method to solve a simple problem. Riot wants more players in low elo for what ever reason? they don't need to even touch matchmaker, they set the cut off for divisions. They set what MMR to Divisions are, they can at any time just change the minimal requirements for Gold or higher represent a small % of players... and as your accusing them of being sneaky and dishonest, well they could make this change with any preseason and no one would ever know due to the soft reset, any inconsistency's between some ones OP.GG MMR reader can be explained away with the simple they don't use riots official Mmr calculations and are inaccurate 3rd party sights.