That's a good point. Though I do think that in a lot of circumstances regular removal of odour is sufficient.

I recently spent a few months in the countryside with very little social contact (a great way to get a lot of deep work done). I would only shower every three or four days and didn't use deodorant. On the first day I smelled fine. By day three or four the accumulation of odour was noticeable. Since returning to civilisation, I've mostly stuck to a shower each day without using deodorant other than when I think it'll be necessary (like if I go out dancing).

I didn't claim it prevents odor. Which deodorant doesn't do either - you're either masking it with other scents or using an antiperspirant to reduce sweating. It removes odor that soap alone doesn't, which means you don't need to mask your pit smells with perfume or clog your pores with chemicals when used daily. It keeps things in check.