I was originally a skeptic. As you get your workflows dialed in, it easily doubles my productivity. I am pretty skeptical on tech fads but this is no fad. Doubling productivity may even be conservative.
I use LLM assist on coding regularly in my current project. It is enormously useful. Saves me huge time, for all the reasons you discuss. I use Tabnine (can select different AI's, but am using mostly Claude) hooked into my VS Code environment, supplemented occasionally by Gemini and Grok. Working in C/C++ for a microcontroller and TypeScript for client side code.
I picked Tabnine because they say they don't keep all your interaction and utilize it.
So useful in not just writing some snippets of code, but suggesting what is wrong with code based on complicated error messages, getting right to tricky api information without digging through dozens of web pages if I did a normal search, suggesting or discussing architecture options, explaining a segment of code that I highlight, critiquing code segments, giving information on what are the leading libraries to use for this or that, giving suggestions for most-used extensions for VS Code for what I'm doing, giving me info on where to get to a setting or functionality in VS Code, etc. Gigantically helpful.