This is more in the realm of psychology/sociology + behavioral economics which is a bit beyond my normal remit.
Some thoughts:
I have talked to a lot of retired folks over the years in the UK and the dividing line is pretty much always class when it comes to attitudes (I call it "views" because they tend to be based on internal biases).
The wealthier pensioners:
£10k is basically a rounding error for them when they have DB pensions, no mortgages, and 2M in investments. £10k is basically another cruise for them.
Below them however you will find:
The professional class (normally Drs and Accountants) who have DB pensions, and no mortgage. Less in investments. £10k for them simply makes them even more comfortable.
The top two groups are about 20% of folks.
Below that is when you get attitudes based largely on ideology going back decades. The "I paid in all my life" brigade comes from this group. The wealthier ones don't really care to that extent.
I don't begrudge POOR pensioners their state pensions (thats fine and you will not find many younger folks that are against this), but the dividing line must be those pensioners that actually need help given that the country is actively getting poorer due to demographics and pension liabilities that keep getting uprated far faster than real GDP growth.
And that precisely is the problem that I have seem in many countries over my professional career.
When pension uprating is not linked to real GDP growth, pensioners become disconnected from the success or failure of the UK economy. This is extremely dangerous socially and economically as it creates increasing inter-generational inequality, which further destabilises intra-generation inequality amongst the working folks.
You see this now when we have 0% real GDP growth and pensioners are still getting a 10% uplift (April 2023), and another est 7% uplift next year in April 2024.
Those payments are actively crippling the UK economy further after the shocks of Brexit, Pandemic, and Ukraine War.
This then makes the country stagnate (investment drops) and then poorer and poorer (as pensions crowd out other spending like education and healthcare).
And then, when the situation has gotten bad enough the State turns on those folks (pensioners) as the country is basically broke and needs revenues to invest.