$350k includes the salary but also all of the health insurance benefits, taxes, stock options, office space and perks, compute hardware, software services… the works. An employer will have an averaged overhead factor for their skilled workforce, which can be anywhere between 1.5 and 2.5 typically. A worker with an annual pre-tax salary of $140k could cost Google $350k in overall expenses per year. Labor is expensive.

Also, these people weren’t just making simple Python scripts. Most of them were contributing core functionality into Python itself and managing the internal Python version and the ecosystem of Google software stacks that depend on it.