Ment, but what do they get in return? Exile might not be desirable, but Terror Shout reduces morale by -5 and luck by -10, which I think is pretty good!!!
And you can play Singleplayer however you want. For example, I never level up to Champion level because I play for speed and efficiency, in the same style as in Multiplayer mode. The game simply doesn't reach the Champion level stage.
As I wrote above, what's the point of having a variety of heroes and a skill tree if everything is always leveled up to Champion level, following the same scenario? There's no point. The efficiency of this approach is also low. It's just a fun option for those who like super-perks. It's like a luxury; it's useless, unprofitable, and aimed at a narrow circle of people who appreciate it and are willing to pay for it. In some cases, as Ment noted, there is an opportunity to level up profitably for Champion level (if all the relevant perks are useful in this game and with this setup). But this is скорее an exception than the rule. Going for Champion level is just a development path for some builds similar to Champion level, in case the game drags on.