No, not every purchase is taxed, and not every purchase that is is taxed at the same rate.

These rates are set by individual countries (because “Europe”, lol) and can change year to year. For example Ireland doesn’t tax books, basic food staples, children’s clothes, medicines. Heating fuel is taxed but was set to a reduced rate during the cost of living crisis. Other countries will have different priorities.

VAT ensures that even those who have a large amount of wealth accumulated without “income” also contribute to society.