I'm confident you have not used Cursor Composer + Claude 3.5 Sonnet. I'd say the level of bugs is no higher than that of a typical engineer - maybe even lower.
In my experience it is true, but only for relatively small pieces of a system at the time. LLMs have to be orchestrated by a knowledgeable human operator to build a complete system any larger than a small library.
In the long term, sure. Short term, when that happens, we're going to be on Wile E. Cyote physics and keep up until we look down and notice the absence of ground.
That last point represents the biggest problem this technology will leave us with. Nobody's going to train LLMs on new libraries or frameworks when writing original code takes an order of magnitude longer than generating code for the 2023 stack.
With LLM's like gemini, which have massive context windows, you can just drop the full documentation for anything in the context window. It dramatically improves output.