Earlier quoted context omitted.
As long as it is compulsory, it is a tax. Whether it goes to your health problems or your street is irrelevant. If you have no control over the money, it is a tax.
Taxes are free to spend for the government, that is they are levied for whatever action or property the legislators choose to tax. Social security, retirement and health care plans are bound to a purpose and cannot legally be spent on other purposes. They often are compulsory but for example in Germany, health care is mandatory and regulated, but the money does not go to the state but rather to a provider of your cho…
In the same way, donations are not tax (but because they are just contributions to the welfare, they are tax-deductible).
Compulsory Social Security payments to the Government are as much tax as VAT.