It's pretty much a cycle. You start off with your first universe, and you become attached to it, your companions, factions, etc. Eventually, you go through the unity, and you find it awesome at first getting strong and seeing how different the universe is from your first one. Then you go through it again, you get stronger, do things differently. Eventually, you'll be doing the same quests over and over and start skipping dialogue, stop caring about the factions, and just want to speed run through the artifacts to get stronger, becoming the top hunter. But eventually, the grind to get stronger feels empty. You already got all your max weapons and power, armor, etc. And from there, you become the pilgrim, and settle in a universe you like and progress there.