You are mistaken. Currently, the higher income you have here, the higher tax rate you have, where the highest tax rate on income sits at 47%, which you get hit by when your income is above 300K/year. People between 60K and 300K sits at 45%.
And then there are regional differences, someone in Andalucía don't pay the same amount of taxes as someone who lives in Catalunya for example, where the top tax rate is 50%.
Even taking into account other taxes we have, you still end up paying more in taxes the more you earn, unless you start engaging in schemes to lessen your tax burden, obviously. Although the social security is capped, so it does increase slower once you go beyond the cap, but it doesn't start regressing which your comment hinted at.
Edit: important to note that the tax rates are all marginal tax rates, maybe that was a bit unclear.
Ignoring smaller tax brackets, income in the bracket of USD 48,500 to 102,900 is taxed at 41% with any higher earnings taxed at 45% [0].
On top of that we have 15% VAT on essentially everything we buy. Also, any "luxury" imported item, including all electronics, also has an additional substantial import tax on top of that, e.g. an iPhone is something like 9%.
It gets even worse though, if I want decent quality health care, education and security I have to pay for all of those privately. Between my wife and 2 small kids, we pay at least USD 10,200 extra each year, and that's not including occupational, speech and physio therapy my now 5-year old, but prematurely born, is needing at the moment.
An "advantage" for someone like me though is that a very large portion of our population is very poorly educated and thus cannot demand much of a salary, meaning that the domestic cleaner/child minder I employ is very affordable.
Just the other day someone pointed out that the middle class here might not get much for their taxes (as we're essentially subsidizing the majority who are poor such that they tend to pay nothing except VAT) but on the flip side we wouldn't have domestic workers and gardeners be as affordable.
[0]: https://www.sars.gov.za/tax-rates/income-tax/rates-of-tax-fo...