It surely depends where you earn £100k. In my part of Scotland you could buy a large 4 bed detached with garage for £300k.
Earning £100k here should get you a decent lifestyle (although there are also fewer opportunities paying that level).
100k in London is not going to get you the same, especially coupled with childcare costs.
The cliff edge for this is ludicrous and disincentives people, especially those in senior health care roles where you can opt to work fewer hours.
I do think that a bit like working to pay nursery fees, it is important to keep in mind the longer term benefits. But then taxing pension contributions goes against this.
I feel people in certain situations at this level do have a right to moan (though should remember that south east house prices give you choice in where to move should you choose to in a way that living in a cheap area doesn't). However it's all well and good saying you could move but most people are tied by other factors like family, schools etc.
In terms of the budget, we now earn the equivalent of two full time minimum wage jobs (although I don't have to work full time hours for mine). We are doing fine because of low mortgage, one older car and have always been thrifty. But it does still annoy me that we qualify for nothing (I don't want or expect it) but that my neighbours inn council housing and no work have a brand new mobility car outside and a newer version of the car we drive, despite the fact they don't work and only he can drive. It's been there a year and she's never had a driving lesson.
It feels like the incentives to work hard are decreasing at all levels.