Attendance Allowance is for pension-age adults, PIP is for working age
Attendance Allowance and PIP are separate non-means-tested disability benefits for different age groups. Attendance Allowance is for people who have reached State Pension age. PIP is for people aged 16 to State Pension age. You cannot receive both at the same time.
If you were already receiving PIP when you reached State Pension age, your PIP award continues. New claims after State Pension age must be made as Attendance Allowance.
Why claiming Attendance Allowance is often worth doing even when other income is decent
A common reason for not claiming is the assumption that income or savings will disqualify you. That is wrong, Attendance Allowance is non-means-tested. The only eligibility tests are age, residency and the care needs threshold.
Even if the weekly payment itself is modest relative to other income, the bigger impact can be in what it unlocks: the Severe Disability Addition to Pension Credit adds £81.50 a week on top of Pension Credit if you receive Attendance Allowance and no one claims Carer's Allowance for looking after you. That alone can be worth more than the Attendance Allowance itself.
Lower rate and higher rate, what the care conditions actually mean
The lower rate is for people who need frequent attention throughout the day in connection with bodily functions, or continual supervision throughout the day to avoid danger, or repeated or prolonged attention during the night. The higher rate requires both day and night care needs, or being terminally ill.
DWP considers reliability and frequency. Needing help with washing, dressing, eating, medication or getting around the home on most days is the relevant test, not occasional help or general supervision.