You already answered your own question. Testing and trust have always been the most important part.

This has nothing to do with LLMs. There have always been plenty of solutions that are more capable, but untrusted.

Your real question seems to be whether you can prioritize better. What are your project goals? If you have no say in or insight into those goals, you have an even bigger problem. What are you even working on?

For sure, you don't want to be maintaining your dependencies. LLMs make it trivial to rack up insane amounts of technical debt. Why is that appealing to anyone? How is it meaningfully different from the idiots wanting to fork everything on github and copypasta their way to startup success over a decade ago?