No. You can absolutely build things with AI small or large and understand it. If you don’t understand it. Then you’re not caring about the output to begin with and not guiding it to build the solution you want.

The word "understand" seems to mean something different to you.

If I understand something, I could write it in assembly if I wanted to. It might take a long time, but I know every level of the stack under my code down to bare metal.

Maybe an AI level of "understand" i.e the same understanding a Senior has of a Junior's code based on daily check-ins is enough for 95% of "boring" programming. But for some tasks you need to either fully understand the code or just tolerate bugs.

At the level of complexity I work at, it's (often) faster to just code it myself than to expect AI to converge on a result I like and then hand check it.