Fair enough. I stopped cheating years ago. As you say, you don't keep playing a game long after you cheat on it.
But even on a single player game, there are forums like on itch, or other places online where people can show off how well they've done. It might be disheartening to someone seeing a player who has everything maxed out even though this is impossible without a time machine.
*****
I have been thinking.about another character for the Sanctum, one related to the Soul Creator. It would help players to both train lower level Souls and get further into the Outerworld.
I want to start each run at as high a level as possible, but I can't due to the level limitation of my characters. I understand that this is intentional, but it doesn't have to be the case 100% of the time.
You could have Soul Creator's apprentice/master/brother/wife etc. (lets call it Soul Master for now.)
What it would do is collect your ultimate team.
Each time you come across the Soul Creator in the Outerworld you can select new members. But you could choose to send one or more of them to the Soul Master. So as you progress through the Outerworld, building your low level characters, you are building a team of your best characters with the Soul Master. Once you have your best team and your current team is defeated, your next Outerworld run could be with your ultimate team at the highest level that your Porto portal level will allow.
I think this would make players use lower level characters more often as they know that in doing so, they are potentially preparing themself for a great alternate team, while bringing up the level of all the characters that they tend to avoid using.