Because VCs work by pushing for high returns on some of their investments, not low returns on all of their investments. They therefore push for business decisions to force high growth, when there can be a better chance of success with a slow burn in some situations. So you end up taking business risks to chase high growth, instead of simply focusing on a niche market to stay profitable, and having a flexible timeframe for growth.
As an engineer, this does hit the paycheck directly - if they go hire more devs to speed product features to market while at the same time increasing sales and marketing... it can change from a bootstrapped model with no end to the runway into a situation where you do have a runway, and it is counted in months, not years. Instead of steady pay with plenty of time to deliver new product, I'm being pushed to deliver quickly, and if we fail, we're unemployed.
And yes, we probably get lower salaries for that model because we are taking less risk. But steady, lower stress work is desired by some of us, and a small bootstrapped group delivers it better than a VC.