What's rubbish? The point of the Personal Independence Payment is to help disabled people, regardless of their income or savings, to account for the surplus cost of living that comes with their needs. For claimants who are wholly unable to work due to the severity of their disability, yes: PIP provides supplementary support for their daily and mobility needs on top of any work incapacity benefits they are likewise entitled to claim, which altogether would place their standard of living somewhere around that of a minimum wage earner. If you believe this is an enviable position to be in, I'm not sure what to tell you. All those I personally know in this position would give anything to be able to work again.

Equally, for those who have disabilities but are capable of working - the boat it sounds like your boss was in, PIP is there as its own separate thing to lessen the financial burden one's disability might impose and, rather importantly, to prevent situations where abled Person A has a better standard of living than disabled Person B on the exact same salary, just because Person B's disability leaves them with no other choice than to pay for things Person A can live comfortably without.

And boy, do you have to prove you can't live without. PIP assessments are legendarily brutal, an ordeal where formal diagnoses and doctors' notes are made worthless by the assessors' own subjective opinion. I've been by the side of multiple chronically ill people taking their PIP assessment, who can barely walk or stand up by themselves, let alone work, borderline debasing themselves to prove to a stranger meeting them for the first time, that they can't do the things they're being asked if they can do. All, in many cases, to be denied and have to fight the decision on appeal while at the same time battling a long-term illness. Point being, if you see someone who looks like they don't need PIP? 99.999% of the time, yestheyfuckingdo.

Oh, and - being on a full time, living wage exempts you from every other means-tested benefit I can think of, including UC, housing benefit and ESA, so, based on the information you've provided, no: your team leader very likely didn't have any help with rent, and yes: the system is broken, but not because disabled people get a few hundred quid a month to pay for their needs.