I think what is amazing to me is how well a developer can do without the bigger picture. It's kind of amazing that you can just write code and that it does what it says on the tin is usually good enough!
Sometimes this will cost you, but a good architect may save you!
I've know good developers who write excellent code, great tests, etc. but that struggle to figure out how their code is built, packaged, and run in various environments.
Likewise, they don't really understand databases, load balancers, and the other surrounding pieces.