Using an sort of boosting service in many games can be seen as unfair and gives an advantage to players. These types of advantages shouldn’t exist in a game based on skill and should attempt to be removed. League of Legends and other online video games have not taken the correct measures to ensure that no unfair elo boost is being given to players. This type of boosting can date back to games such as Halo 3. Players would intentionally lose games in an effort to trick the ranking system into giving their team more Elo for the win and causing a larger jump in ranks. This happened so much that it ended up being that who ever had the most losses would be pre-determined to lose the game by the system and if they won they would receive more level experience or elo and rank up faster.
In League of Legends it is quite similar. Players are set in ranks based on Elo points. After a certain number of points through wins you are able to move up in ranks. This can be exploited as well by playing with someone in a higher level Elo than you or playing with another person on a smurf account and winning games with you. Now the person playing with you and on your account are likely Diamond rating or higher in the game meaning they have experience playing League and know how to win. You also aren’t there to weigh them down and they will rank your account fast and effortlessly.
Elo type boosting will likely be around forever. Every game has different algorithms that determine how much Elo you get but it all comes down to general things like the ranks of the people you are playing with. How well you did in the game and how fast the game was. All these types of things determine the win and after testing you can figure it out on your own.