it also exploded due to the growling size of such companies and dominance relative to overall US economy, especially post-2008 in which there was a void filled by the collapse of the housing, auto, brick and mortar retail, and financial sectors (except for Walmart, biotech, payment processing, and information tech, everything else weas hurt badly). such companies play a much bigger absolute and relative role, whether it's shopping, cloud and data infrastructure, advertising, AI, etc.. Companies need to pay top dollar for top talent to get products to market before an equally-sized trillion-dollar competitor does. Due to network effects, speed is of upmost importance.