You need more than two incomes worth of salary in any country that does income tax bands. In the UK, two people earning 30k each will take home a combined 50k. A single person needs to earn almost 70k to take home the same. And for council tax you end up paying 75% of what an entire household would pay.
In the US, two moderate incomes see a similar federal tax bill to a single person, with things actually getting worse at higher incomes for the married couple. Is the UK tax code really that different?