There is very little short term detailed planning in an actual formal business plan. It remains very much at the strategic level and is mostly about your value

There is very little short term detailed planning in an actual formal business plan. It remains very much at the strategic level and is mostly about your value proposition, your go-to market strategy and financial projections (which necessarily include market sizing). All of these things are actually part of the YC interview. I agree with OP that PG’s comment is somewhat disingenuous.