In order to persuade players to engage with new content, they need incentive. Getting more powerful is one way to incentivize players to engage but it is not the only way. Most incentive is built around the players’ motivation. Getting stronger is not the only motivation for players in games - several games notably don’t focus on getting stronger, and instead add content that increases the overall potential choices a player can make instead. The Sims is a great example of a long-running game that doesn’t have power creep in any conventional sense.
Power creep isn’t inherently a bad thing. Power escalation is a good incentive because lots of players like getting more powerful. This new power is also often accompanied by new content that requires higher overall player power levels to engage with. As long as it is properly managed, power escalation can be a sustainable incentive to engage players for the entire lifespan of a game. World of Warcraft is approaching its 20th anniversary and each expansion continues to raise the bar on overall power levels.
In such situations, managing the power creep such that the user experience doesn’t feel bad is what matters far more than extent of the power creep itself. The player should feel the upgrades they earn are substantial through the content they engage with, usually shown through the time it takes to defeat enemies and reducing the difficulty in surviving those encounters. There’s also needed UI management, such as making sure that the displayed numbers don’t get too difficult for players to intuitively understand - it becomes a lot more difficult to tell whether dealing 18120110845183115 damage is a lot or a little compared to a monster that has 123319051501581591364 health than it does to deal 181 damage to a monster with 1233190 health. There are a variety of ways to do it. Managing power creep is not an insurmountable task.
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