I just spent the past three hours debugging a long latent bug from vibe coding a thing. The only way I found it was running a debugger through the C++ code and tracing everything -- Claude was utterly useless until I basically pointed out the problem to it. I don't think understanding technical aspects of programming is a waste of time at all, it's still very necessary. The annoying thing too is that, whatever time I saved having the LLM write it, I pretty much just lost having to debug it. (For what it's worth: the bug it introduced is one I never would have introduced on my own, because it fundamentally misunderstood a key component of the design)