The point being made here is that a developer that can only do their primary job of coding via a hosted LLM is entirely dependent on a third party.
You make a good point of course that independence is important. But primo, this ship sailed long ago, secundo, more than one party provides the service you depend on. If one failes you still have at least some alternatives.
That said I only find google results somewhat helpful. Its a lot like LLM code (not surprising given how they're trained), I may find 5 answers online and one or two has a small piece of what I need. Ultimately that may say me a bit of time or give me an idea for something I hadn't thought of, but it isn't core to my daily work by any stretch.
Spoken from a fair bit of experience doing software development in closed rooms with strict control of all digital devices (from your phone to your watch) and absolutely no external connections.
There are moments that are painful still, because you'll be trying to find a thing in a manual and you know a search can get it faster - but it's silly to imply this isn't possible.
And it's not like people weren't able to develop complicated software before the internet. They just had big documentation books that cost money and could get dated quickly. To be clear, having that same info a quick google search away is an improvement, and I'm not going to stop using google while it's available to me. But that doesn't mean we'd all be screwed if google stopped existing tomorrow.
I mostly write JS today and it either runs in browsers (dependencies) or a host like AAwS (dependencies). I use VS Codium and a handful of plugins (dependencies).
These all help me work efficiently when I'm coding, or help me avoid infrastructure issues that I don't want to deal with. Any one part is replaceable though, and more importantly any one part isn't responsible for doing my entire job of creating and shipping code.