Making a VSCode fork is probably the wrong direction at this point in time. The future of agentic coding should need less support for code editor related functionality, and could eventually primarily support viewing code rather than editing code. There's a lot more flexibility in UI starting from scratch, and personally I want to see a UI that allows flexible manipulation of context and code changes with multiple agents.
GitHub is building a UI like this. I like it. I sometimes need the full IDE, but plenty of times don't. It's nice to be able to easily see what the agent is up to and converse with it in real-time while reviewing it's outputs.