You're still perpetuating this myth that it is about the tools, when every interaction I've had with coding assistants and LLMs veers into the territory OP describes. To be fair, the work I am doing is pretty complex and novel.
And I use a wide range of model/versions.I mostly use Claude, from 3.5 to the newest 4.0. I also use Gemini and with Copilot.
It's not a myth. I don't promise that better tools solve every problem but it can increase quality and usefulness of the output. One of the main big problems of (nearly) all AI coding tools is to get enough context of understanding which means the right files for a prompt need to be send along. Especially the bigger a project gets the more important that is. It's kinda an AI in itself just to gather the right files for the main AI prompt which is sent to the main solving AI. E.g. in aider I specify manually which files will be sent along the prompt and they are not truncated or ignored, something which can happen easily in tools like Copilot, Cursor, even in roo code behind the scenes. This leads to the result that the main AI does not see the whole picture of the project and makes wrong guesses and maybe assumptions.
More details in prompts in every tool help find the AI to understand the bigger picture and the important files. It maybe even helps to describe and save the whole project and structure in a text file to describe it to the AI better along every prompt.
Roo code is smarter with this problem, Claude Code is also pretty smart with it and in aider the problem does not exist if you as a human understand the project structure and tell aider the important context files to send to the AI.
And I use a wide range of model/versions.I mostly use Claude, from 3.5 to the newest 4.0. I also use Gemini and with Copilot.