Why is it important to scale Auto and Category campaigns in your Amazon advertising?
Unless you're repeatedly checking the auto-complete and combing through SERPs multiple times per week (99% of you aren't doing this, agencies included)...
You are not going to outperform a scaled Auto or Category campaign when it comes to discovering new product and keyword targets.
So if you don't want to do the extra leg work in terms of research, it is essential to have these campaigns spending, and spending well.
Otherwise you could be at a big disadvantage, because you won't be advertising on emerging keyword and product targets.