We got ZIRP because Western governments decided to play “kick the can” after 2008, and most lowered rates as close to zero as they could get away with while engaging in quantitative easing. This created an environment where lending was very cheap, effectively “free money”. IMHO this along with the contemporaneous smartphone/internet services boom is what lead to the previous environment, where you could afford to take on many failures as long as you had a few unicorns. Now that the industry is mature and funds are tighter, this approach doesn’t make sense anymore.