That's basically the same system in many central European countries like Denmark, Austria, Germany, Netherlands etc. A relatively high tax rate that starts at comparatively low salaries. The 50% tax rate starts at a much lower income level than the UK or USA. So technically, they are not really taxing the rich but just average middle class people. Those on low six figures (good but far from millionaire status) effectively only take home 50% of what they earn.
Obviously there are some complaints across the board because people still do the same amount of work and are taxed much more heavily compared to other countries. But the upside is that state infrastructure works well, the health system is robust and there is very little crime because of generous welfare programs. Paid maternity leave is much longer, up to 1-2 years. Quality of life and happiness is higher on the whole.
But those countries don't have the same inequality as the UK & look at social mobility here. The housing market and the fact it's so entwined with the economy has created huge issues.
"Wealth in Great Britain is even more unequally divided than income. In 2020, the ONS calculated that the richest 10% of households hold 43% of all wealth. The poorest 50%, by contrast, own just 9%"
"By 2023, the richest 50 families in the UK held more wealth than half of the UK population, comprising 33.5 million people"