Craig Kerstiens:

I’ve learned a lot of skills over the course of my career, but no technical skill more useful than SQL. SQL stands out to me as the most valuable skill for a few reasons:

1. It is valuable across different roles and disciplines
2. Learning it once doesn’t really require re-learning
3. You seem like a superhero. You seem extra powerful when you know it because of the amount of people that aren’t fluent

I tend to agree. I still use (and sometimes love) ORMs and database libraries while building apps, but the more I’ve learned SQL over the years, the more I appreciate it for what it is.

Craig drills into each of his 3 points above in this excellent post.