Why is the sole income of the family father no longer enough today to support his family of four?
Because the tax burden rate does not indicate what you or your parents actually have left of your income, but relates taxes and levies to the GDP.
In total, more taxes and levies are collected, but there is also overall more "income" (on which these taxes and levies are imposed) available. The percentage ratio is stable. Therefore, it is not correct to claim that generally more taxes and levies are collected today.
If, as the sole earner, you can no longer support your family, this basically means only that your income is burdened (percentage-wise) more heavily than that of your father. Conversely, this means – considering the stable rate – that someone else's income is less heavily burdened.
Who could that be?