California does have some legally guaranteed entitlements if (edit) there is a mass layoff. Apparently like this case if a company just goes under with no money left that doesn't apply. What is the situation in Europe? The healthcare continues, but if a company has no money who pays the entitlements? Do employers have to fund a reserve? Or the govt pays?
In Australia (where I'm from) companies are legally obliged to keep enough cash on hand to cover employee entitlements, which at minimum is pay for the notice period + accrued leave + superannuation (may be more depending on your contract and time served with the company).
Above that, employee entitlements get paid out first in the event of bankruptcy/wind-up (i.e. before any investors or creditors see a cent).
Also, any director of a company that doesn't comply (i.e. keep enough cash on hand) is likely to 1) get banned from being a director of a company, 2) prosecuted, and worst of all 3) get reamed by the tax-office for the amount owing.
Healthcare is almost entirely public here. Employer-provided private health insurance is rare.