Then the situation is maybe not so different? It's an amount you're entitled to when laid off, set by the government, which your employer has to fund proactively (payroll taxes).

Because it's set by the government, it caps out at well below a typical tech worker's burn rate, so it's little more than a brake on the depletion of our savings. When a tech company offers severance it's typically much, much more than what the government guarantees.

You also get the full amount regardless of how long you're unemployed, so e.g. if you get laid off with 7 weeks severance and find another job in 3 weeks, that's a free month of salary.