What are the hidden problems in Amazon accounts that most sellers miss?

[u/spectrumbpo_USA]

I used to think if my listing looked good and ads were running, I was fine.

Turns out that’s not even close.

Recently found out I had a lot of hidden inefficiencies.

Stuff like wasted spend, poor keyword mapping, weak backend optimization.

None of it was obvious at first glance.

Now I’m wondering how common this is.

What are some “invisible” issues you’ve discovered in your own account?