of course 100K doesn't go as far as it did 10 years ago neither does 50k, 30k or 20k
100K in London doesn't go as far as 100K in many places outside London
also moving from 99,999 to 100,001 results in some pretty steep knife edge tax rises
The same happens at around 27K for many as suddenly your extra £1000 ( 680 after tax and NI) a year has to cover paying student loans, no council tax help no FSM, no help with dentistry or eyecare or prescriptions, no uniform grant etc all the above cost way more than your £680 a year extra in your pocket so often the tiny promotion above NMW leaves you worse off
student loans repayments are taken out before tax and are payable when you hit 27K which is not much above NMW so people will be repaying loans on 30K and 50K
childcare costs are not totally paid for; free childcare is often offered at set hours (9-3) so if you need more childcare ( because you have to be at work for 9 and can't leave before 5) you are still paying for it even at NMW there is a limit to the amount you can claim surprise surprise this is less than the cost of childcare! it is the same with housing benefit it will almost certainly not cover the costs as most rents are way higher than the allowance
if you are a single parent with 2 under 5 on 100K you will not have much spare cash, and it will seem like you are not much better off than those on 40-50k
however statistically the more you earn the less likely you are to be a single parent
if however you are not a single parent and earn a 100k , you will either have a SAHP so no childcare costs or the other parent is also working so you are not bearing all the costs yourself and your household income is well above 100K
being single on any salary at all generally means you are worse off than a couple sharing the same income so 2 people on 50k will have more take home than 1 person on 100k but so also will 2 people on 25K have more than one on 50K
also generally a single person's bills will not be half a couples bills, while food and transport and a mobile phone will be roughly 50% council tax will be 75% and
heating broadband TV licence etc will be the same
Most people's gripe is not that 100K is untold wealth it is just some people's refusal to acknowledge that they are in the richest 2% ( about richest 7% in London) and so are way better off than almost everyone else; also the cost of living rises hit poor people most as often it is next to impossible to cut bills any further
if you are feeding a family of four on £70 a week trying to cut 10% off that is really hard if however you are spending £200 a wek on food reducing it by 10% is much easier