Its all about the context window. Even the new Mistral Codestral-2501 256K CW does a great job.
If you use cline with any large context model the results can be pretty amazing. It's not close to self guiding, You still need to break down and analyze the problem and provide clear and relevant instructions. IE you need to be a great architect. Once you are stable on the direction, its awe inspiring to watch it do the bulk if the implementation.
I do agree that there is space to improve over embedded chat windows in IDEs. Solutions will come in time.