People can change at human timescales. Businesses die at business timescales. Business timescales in technology are shorter than human timescales. So, lower downs could become higher ups, but not by the ship date.
Small project timescales are shorter than human timescales.
I've had my current job for 7 years. Most of our work in in SQL. When I started I went from knowing approximately nothing of SQL to being productive to helping other team members in a few months. This matches what I've heard in other places, that it can take 1-6 weeks to become minimally productive (as in, not a net loss to the team) in a new language and 6 months to become competent.
But, my employer is not a Startuplandia single-project exocompany. We haven't renamed "project manager" to "CEO" or "Director" to "Investor". We have an actual sustainable business model, rather than "exit or bust". We have people running the place, who have been around long enough to understand beyond the latest hype cycle.