- Early-stage fundraising. The numbers are wrong, everybody knows it, but you have to show that curve going up and right.
- Later-stage (maybe 1-year post-revenue?) when there is some level of robustness behind the numbers, and you do it because it's useful to pilot the company
Rational financial planning is, of course, essential for managing a business sensibly.
However, vague intuition + random luck generator + huge uncertainty != a useful financial plan. I feel like a lot of startups could summarise their financial slides with something like "We anticipate an outcome somewhere between failing within three months and becoming the next Facebook, with somewhere between Ramen profitability within six months and a unicorn exit at 8-10 years being most likely."
Personally, I have found it hard to work with pre-revenue companies, especially if they come to me with a plan to hit tens of millions in revenue in just a couple of years since launching. Maybe a small percentage of them do, but given how many don't make even a single dollar I've tried to steer clear of pre-revenue startups. Companies with real revenue and growth seem to be a much better fit.