Marginal tax rates in the UK are slightly higher than they are in the US. That makes sense, since the UK has a more comprehensive welfare state than we do, even after years of Conservative government. There isn’t a glaring disparity that clearly calls for taxpayer relief.
But Liz Truss clearly wants a big tax cut at a time when inflation and the deficit are uncomfortably high, interest rates are rising, and the pound is plummeting. If she gets what she wants, the increased demand (largely for imported products from countries with whom she is effectively threatening a trade war) will make these problems worse. Pouring gas on the fire will result in the stagflation of ’79, not morning in the UK.