Even with a half a dozen or two dozen eyes on the thing, there are still mistakes. It irritates me to no end. Even traditionally published books have errors. This is mainly a cost saving method after the galleys. There are a limited number of passes they[publishers] are willing to pay for.
The same is true for indie published manuscripts.
It's our flaws that makes us unique, isn't it? Sometimes this is correct, but not where writing is concerned. Your writing should be flawless. So how do you get there from where you are now?
I don't know about you, but I've got enough gray hairs and bald spots from the editing process. But still, I go through the motions of thee editing passes, critiques, beta readers, and my own final editing pass before submitting a work for publication. As pain stakingly as I try...Still there are errors.
Some things to remember when editing...
Is easier to erase than...
is not as colorful, but is inherently better than...
Keep writing and loving the Lord.