You don't have to bend to every VCs demand. WhatsApp ran very lean and perhaps had 50 engineers tops. Every big tech company ran very lean until they hit scale Series D or so. So the headcount growth is not just a function of VC, but a function of people's desire to build empires. Even in many social gatherings managers boast of the number of engineers they are managing. So it's another flaunt metric for a bulk of founders and managers. Don't just blame the VCs.