During the Mecha Kingdom event series, the majority of players purchasing tokens had no trouble grinding for token points (heroic points) to unlock the Prestige Garen skin.
The ease with which players could reach the required token milestone diminished the value of the Prestige skins obtainable through the event series; therefore, Riot Games decided to… raise the difficulty of the game.

Justin “Xenogenic” Hanson – Lead Event Planner for League of Legends, recently announced changes in the newly launched Infinity Galaxy event, specifically the adjustment of the token points received by players, or in short, “raising the difficulty of the game”, making it more challenging for players to earn Prestige skins from this event.
Specifically, in the upcoming Infinity Galaxy event series, the token points received through daily missions and matches will be significantly reduced. According to Riot’s calculations (applicable only to the servers they directly manage), during the Mecha Kingdom event, players only needed 1 – 2 wins per day to accumulate enough token points to unlock the Prestige skin.

However, for the Infinity Galaxy event, gamers will need to secure 2 – 3 wins per day to hope to accumulate enough token points during the event to unlock the Prestige Malphite skin.
Specifically, the token points that players receive will be reduced from 12/6 (12 points for a win and 6 points for a loss) to 10/5 for gameplay in Summoner’s Rift, and from 8/4 down to 6/3 in ARAM.
The rewards obtained from the event mission series will remain unchanged.

Overall, this move by Riot Games has faced quite a few mixed opinions from the gaming community; however, it seems necessary to reinforce the actual value of Prestige skins – which are considered among the most valuable in the game.
Normally, players only need to spend a larger amount than the value of common skins to purchase Prestige tickets, and the remaining task is simply to grind for token points, which is in reality a very easy task; in fact, many players can complete it with only half of the event’s duration elapsed.

This has led to the perceived devaluation of Prestige skins earned through the developer’s event series, and that is precisely why Riot has sought to enhance their value by… making it harder for players.