Without the business, 15 years would be a fair estimate for how long the cash would last, based on modest inflation adjustments on salaries, an average $100k to $125k cost per employee (all in), and either clearing their debt or just paying interest on it perpetually.

They'll probably burn $150b over ten years on employee costs, with 100,000 employees (present count). That's mostly ignoring the destruction of the stock itself, which would hit employee compensation and require higher salaries to offset.