It might be pocket change to Google or J.P. Morgan. In the academic world, those are career making amounts.

And big grants do give financial rewards to the PI. Say I get a $10 million grant; my university will take about $5 million off the top in "overhead" (to be spent on overpaid administrators, student stress counselors, the latino student center, and maybe even education). I turn to them and say "give me a 50% pay raise or I leave". The university then compares the cost of a 50% pay raise to half my grant, and gives me a 75% raise.