You can skip type system magic, and have people just keep introducing bugs that it would prevent over and over, writing more tests trying to prevent it, never quite succeeding, but overall "feeling productive" and "being agile" along the way.

Having said that - yeah, making good apis and abstractions that prevent mistakes takes time and some skill, and pays off gradually proportional to the scale and longevity of the project. And for certain things is not worth it. Being able to make a good judgment if enforcing something at the compile time / runtime / at all is worth it is part of the skill.