As one of the hated Boomers, albeit not yet old enough for my pension*, I'm afraid I have no sympathy for people who want a handout but don't want to fill in a form to prove they're entitled to it. For those with literacy or other difficulties, I would imagine Age Concern and other charities could help with the claim form. We don't expect struggling families or unemployed people to be taken on trust if they need help from the benefits system. Why should pensioners be treated differently?
I am hoping that in the Budget Rachel Reeves will announce that Pension Credit will be made available to more people, ideally with immediate effect. The messaging around this has been poor. I suppose they wanted to alert pensioners before the winter but it's created an open goal for the Daily Mail and other Labour bashers.
Paying out a flat rate benefit without means testing saves a lot of admin costs but they've presumably worked out that even with the extra admin from additional Pension Credit claims they can save a lot of money by withdrawing WFA from pensioners not on Pension Credit, and I think this is the right decision. Lots of older people don't need it. The two I know best (my husband and my mother) certainly didn't need it, and would rather it was used to help those who do need help. The big problem with means testing benefits, though, is that wherever you put the cut off point people just above it are going to feel hard done by. Look at what happened when the Tories decided that Child Benefit would no longer be a universal non-means tested benefit.
*Yes! Boomers are those born from just after WW2, who are still under 80, through to 1964, and those people are 60 this year. Lots and lots of us are not yet OAPs.
PS I see the OP has not returned and hasn't provided a single link, let alone a credible one, to back up the claim in the OP. What a surprise.