Universal Credit Migration

I just received a letter telling me I must migrate from ESA to UC. The letter claimed that they had contacted me about this in March but I never received a letter then. I suspect the DWP is trying to justify implementing Starmer's recent cuts to disabled benefits by inventing retrogressive correspondence to validate the recent changes as if this migration was the DWP's intention before the cuts announcements. Call me paranoid!
Anyway, I took the Benefits and Work UC test and found some of the questions quite bizarre. Is lifting your hands above your head a sign that you have no disabilities and are capable of work? What a bogus question. What if you can put a t-shirt on without lifting your arms? Or you can lift your arms only when held at gun point? Or you're bed bound but can only lift your arms above your head when lying down?
What I'm asking is how do these physical actions establish someone's capacity to work? I am seriously confused about this test.

Thanks for your reply. With ESA I could understand the basis of the questions but I find it very difficult to answer many of the UA questions.
I have incurable blood cancer. It's aggressive and difficult to treat so I need regular body scans on top of weekly blood tests. I'm eleven months into twenty five months of twice weekly chemo and daily immunotherapy. I've had a stem cell transplant and lots of chemo before that. Most people with blood cancer are perpetually having some form of treatment or other.
It is gruelling and has severely disabled me increasing mental health issues along with it.
I feel insulted answering this ignorant and utterly non-clinical assessment that reads like an army recruitment questionnaire. I resent being interviewed or assessed by a bunch of unqualified gate keepers who think they have any idea what it's like being disabled.
How this is not a national scandal like the Post Office and Infected Blood campaigns is shocking.
It's like involving hospital cleaners (no disrespect to them as they do a vital job) in clinical decisions. Unless you have specialist knowledge, not just some generic DWP doctor involved, then any assessment is based on ignorance and prejudice.