Resets are good for the game and the players. It keeps the economy in check, so like Mark Snicket said before, cubits don't cost 10b, or something ridiculous. Since every day billions are being pumped into the economy by massive iron golem farms, it will happen if the resets don't occur.
Furthermore, resets are also a good way of gaining cubits. Prestige resets, along with the seasons, so it's a good way to obtain cubits, because there will be a point, in prestige where it gets to hard to grind. Resets also make sure the realm isn't flooded with items, and, during resets, they also switch versions, to the newest. I mean, items that have the season vault access tag can be transferable through seasons.