Those benefits are not paid by the company, but by the state. That's one of the reasons why cash-in-hand salaries are lower in most "socialist" European countries: the State takes a big fat cut out of it (47% in France), so it can pay for these benefits.
Taxes in the USA are often just as high (remember to add in state and local taxes for an apples to apples comparison with European countries). And for that you get no "socialism" -- no healthcare until you're old, for example.
Income taxes (Federal + CA) seem to be roughly in the same ballpark as France based on [0]. A French income tax simulator is available at [1]. This is the "simplified" version. What matters is box 1AJ for salaried income.
For 100000 USD it's actually a bit higher than for 100000 EUR.
However, as another commenter said, income tax is not the full story - far from it. There are other taxes that you have to pay. Also, while social security comes out of your paycheck, it's considered taxable income in France for the purposes of the income tax. Also, social security is usually insufficient, so you usually have to pay for a separate insurance. Which, you guessed it, isn't deductible from taxes.
As far as a company's concerned, if the employee costs 100 EUR "fully loaded", they only get around 55-60 EUR in hand. Also, when comparing with the US, don't forget that VAT is at 20-25% depending on the country. And, at least in France, VAT is levied on some taxes (yup), like for example electricity and gas.
People forget to count the corporate taxes on the employers in Europe (to support the welfare state) which lowers the salaries of workers making the calculation look like taxes are similar.
