It's not simply that "the Government save money". We all - taxpayers- pay for the State Pension. Average life expectancy for a male retiring at 65 is now approaching 20 years , more for females. This figure has increased by some 60% (from circa 12 years) over the last 50 years. So State Pensions are becoming more expensive as time goes on. Compulsory retirement at age 65 does not suit everyone, many want to - and can - continue working.
Ultimately all the SW benefits have to be paid for. The "rich" can't pay for everything (despite what SF, Paul Murphy, Solidarity et al might suggest).