-si- Lifetime is not so bad, but annual allowance is a squeeze. When the limit was 110k for tapering of lifetime allowance (its now 200k), that taper, combined with the taper of personal allowance over 100k (effectively a 60% marginal rate of tax) and at around 121 k the effective tax rate was over 100% of income.
With IR35 clampdowns people were having to pay to come into work. Given that at that level most of the work is discretionary extra work, people just stopped doing it.
The next problem is that what you pay into a defined benefit scheme from your salary is not what counts. It is the deemed increase in the pension pot that counts.
Say you earn 54k a year. Your annual pension in the defined benefit scheme goes up by 1/54 of your salary for that year, so 1k / year. You have paid 12.5% of your income into that (£6750 over the year). But the deemed increase in our pension pot that year is actually 16 times 1k - so you are deemed to have put in 16k.
Still not biggie. But if you have a final salary scheme and your salary jumps (say at an increment point) then you can very quickly get to over 40k.
Say your salary went from 15k to 20k and you had 15 years in the final salary scheme. Forgetting about any contributions you make in the year after your salary increase, you are deemed to have made 15k contributions. Its complicated and horrific and what usually happens is people bimble along quite happily and then get completely shafted by a pay rise.
Add in a load of other peculiarities about how junior and senior doctors pay is calculated and what is pensionable salary and what is not and it quickly becomes a mess