What might be wrong with planning a story?

I'm uncomfortable with planning a story. I get especially uneasy about using a system to plan. An outline is already a system and that's uncomfortable enough. But it seems worth trying.

I worry mechanical planning might result in a story that's boringly predictable. That seems likely if I'm using the mechanics of tropes. But if I'm using some other mechanics, it might be fine. If it's just reverse/forward planning, and hitting beats, maybe that's fine. As long as it makes sense and isn't hitting every point on The Hero's Journey in the most superficial way possible—it's probably okay for practice, at least.

And anyway, I might need to write stories that are a bit more predictable. After all, a problem I've run into before is that the story felt too all-over-the-place or confusing. Predictable would be a change of pace if nothing else.

Why would it be bad, though, if it were predictable? Someone might not like it and stop reading, I guess. But that's fine if I'm writing to practice planning. Yet it still feels a bit uncomfortable. Why? Maybe because I might get bored with it before the reader does.

I used to worry I'd do bad work if I was bored with the story, or not actively inspired to write it. I don't think that's true now. Writing every day has shown me that even when I'm bored shitty, I sometimes produce stuff that is surprisingly good when I go back and reread it. I don't actually have to be Inspired to write good stuff. Moreover, I can actually write while bored.

So maybe it's okay, workable, to write from a boring outline.