Creatives (designers, engineers, etc.) with optionality (at the caliber that Google would hire) pine for freelance-like working conditions (not referring to pay, but rather creative control, flexible hours, and amenities). These tech firms try to absorb as many of those benefits as possible to woo over employees. In Google's early days, maybe employees had greater creative control over their projects-- hence creating more autonomous and creative working conditions. However, as a company scales, you inevitably lose your creative control and become a cog in the larger machine. No perks can veil this, hence the changing of Googlers' mentalities.

Unless you're at the top of one of these large firms, I have a really hard time imagining any creative and truly autonomous person willing to work for more than a year at any of these institutions before breaking free and either founding a startup, joining an early stage startup, or freelancing.