So, if your salary is 50K and you get your employer to reduce your 'official' salary and they pay you in other ways, how is that not "deliberately hiding things or lying"?
The would be tax evasion and illegal, you can however increase your pension contributions, and avoid paying the 40% tax, when you draw your pension you're likely to paying tax at the lower rate. Also upping your pension contribution reduces the amount of child benefit you lose if you're in the the £50k to £60k bracket.
Child care vouchers, CTW and all the other salary sacrifice schemes are perfectly legal and at your employers discretion. If your employer offers these schemes they can reduce your taxable pay even though you get non-taxable benefits in other ways.
If you don't like it, tough, vote for a politician who's going to sort the tax system properly rather than continually make it more complex to suit themseleves and which ever minority group they're trying to get votes from that week.
When you find such politician let me know and I'll vote for them as well. In the meantime I will continue to avoid paying any more tax than I have to legally whilst I can. Cracking down on the cash economy which is law breaking might be a better start than squeezing a few more pence out of higher rate tax payers who already contribute disproportionately.