Because technology is still in the "land grab" era of business. Say you don't hire during the COVID boom, well, ok, now you don't have to do layoffs but now you have to battle 2-3 new entrants into the market who snarfed up customers you were unable to serve because you were understaffed.

There only "downside" to not hiring is the chance you have to layoff 5-20% of your workforce in a year or so. The upside is tremendous.