1. 3.8.0.2 fixed a logical error in the code. High-level language won't help you if you invert a logical condition or commit some more subtle logical mistake.

2. Our software also needs to be fast. No one needs a slow database engine. There is no high-level language that beats C on tasks like writing sqlite.

3. Finally, show me that unicorn high-level language with strong, automatically provable invariants and one piece of widely used, reliable software that was written in it.

Sqlite works. Testing works.

If there actually was a credible alternative to C for writing software that is efficient and reliable with requirements that sqlite has, I can assure you that people would use it. The problem is: it doesn't exist.