Doesn't that also mean it scales up the negative consequences just as much? More code = more maintenance, risk, bugs, resource usage etc.

Sometimes these things are worth it because the manual process is error prone and perhaps frustrating/stressful (these things can't be measured as easily). But sometimes they are not examined critically at all.

How often? How many? How important? Are there simpler solutions?

Kind of depends on the receiving end of the questions in my experience. Some people are happy if you push back and keep things simple, others have problems with that.

I wonder how much does scale affect these basic principles. I would assume that with scale you already have a lot of problems that push even harder towards not implementing every single thing.