I don’t think subagents are the problem. Uncontrolled fan-out is. Separate contexts and independent analysis are extremely useful for larger tasks. In my experience, Pro is far too limited for sustained programming, although that probably depends a lot on the kind of engineering work you do.

Fable is great, but overkill for most tasks. Sonnet and Opus are already good enough for the execution work. I find Fable much more useful for planning, orchestration, advising, and judgment.

I am not sure. I think of myself as a pro user yet I am finding hard time maxing out Pro tier. It only happens with sub-agents without any material returns.