Frankly you are right about Harry not looking for powerups. What Harry did do, before Changes blew everything up was find ways to make his own power more effective. Hence his shield bracelet, his rings, his gun etc. What he did not do was go around hunting objects of power, and the fact that he didn't I think says something about his character. When we first encounter Harry, he is a kind of happy-go-lucky wizard-for-hire, happy with his tiny apartment, his cat and his joke of a car. What he basically wants to do is help people with his skills and pay the bills in the process. Then things start happening to him, and note carefully most of the stuff in the books is fairly episodic. Harry notices that hings are getting intense and he starts accentuating his abilities, but in a rather limited manner. Now, here, I think is where many readers have a problem. If you are going to up your game, why not take it up several levels? Again the answer is..... Harry. I think Harry, fundamentally just wanted all the shit to stop so he could go back to his previous life. So basically this is denial. And the exact moment this denial vanishes is Changes.
He cannot go back. Ever. But there remains, a nostalgia, an attraction to what he is leaving behind. I dont have the books at hand right now, but go back and read the section
Theres a bit of inner monologue there as he accepts his past is gone, and how much that hurt him.
So, when everybody talks about how Harry should be planning, plotting, ramping up weapons, new tactics, they miss the point. He isn't that type of a guy. He is not a coolly calculating Marconi, or even a Murphy or a Thomas.
Of course this raises the issue that then such a half-prepared, idiot should not have survived the stuff that was thrown at him. And her eI have a crazy theory.
Over the last decade and a half or so, the mainstream in good fantasy has increasingly become the dark-gritty style, with deeply flawed characters and multiple shades of grey. In books like Richard Morgans A Land Fit For Heroes, you actually ask yourself if the protagonist is actually worthy of your support. Essentially the trope of the virtuous hero on a white horse has been conclusively subverted. And we are readers of Malazan. We know all about subverting tropes. Now, what if Jim Butcher had some subversion of his own on his mind? What if he decided to subvert the gritty hero with a retro hero? So we have Dresden, who with all his faults is fundamentally a really good chap. He loves kids and small animals. He is chivalrous towards women. You wont catch him making huge plans like say, Rake, but he wins, coz he is good and when he gets into a righteous rage his power rises. So, what if Butcher, through Dresden is having a little laugh at current fantasy?
This is my own crazy theory and it fits the definition of half-assed beautifully. But what do you think?
As for the number of books, I once heard 23. But this info may be outdated/wrong.