I'm sure it would incentivise if they were getting nothing in pension. Point is, you still need to be able to look after people, and some people are struggling to make ends meet, never mind actually save money. Incentives are moot there. And even if they could save some, do they really know how much they need to save? It's not straightforward, inflation and governments taking away things you thought you'd get forever, can have quite an impact on the accuracy of your forecast of what you need. Plus you don't know how long you'll live.
If your argument is that it should only go to those that really need it, and only when they need it, there's some validity to that. But it gets messy. Someone who owns a house that's worth half a million...well do they now need to sell the house they worked 40 years to pay for, because otherwise they have no income - as technically they have wealth of half a million? Seems quite unfair, not to mention it's not what they were told when they were paying tax into the state pension pot.
For me, I don't begrudge anyone this sort of thing. Those who worked all their life deserve something at the end of their career. Those who need some help, I'm glad that we live in a system that catches them. And it's not as if we don't get benefits from it. Who wants to live in a world where tens of thousands of people have 0 money and 0 income. Their options soon narrow to something none of us wants to live with.
You have a contract with society. Granted you were entered into it without choosing to be. If you're fortunate enough to be able to support yourself for the rest of your life and all possible healthcare costs for you and your family, I suggest you spend some time reflecting on how you got where you got. Hard work, maybe. Did it alone without any help from anyone? Doubtful.
Just as there is a contract with society that the well off pay more and contribute to others well being, there are other forms of the social contract, like the police officer who when facing armed men, still tries to protect civilians, or the paramedics and doctors who go into dangerous situations to help people.
It's sad that people who have enough, and live under this secured umbrella, think that actually, they don't want to give up their taxes for that. Sign of the times I guess.