In my case, I work full time and carry out my caring responsibilities before and after work, at lunchtimes and at weekends. Overall, it probably equates to another full time job, but personally, I wouldn't want to be paid for it because it is not a transactional arrangement. If I had to give up my day job in order to do what was required, then I accept that I might feel differently.
Regardless, my point still stands. I haven't said anywhere that carers shouldn't be paid for the caring work that they do. I think it's perfectly reasonable in some circumstances, and of course any expenses should also be reimbursed.
But the point I was making was simply that any such arrangements - whether relating to payment, expenses or both - should be clearly agreed, appropriately documented in writing and fully transparent to all concerned. That doesn't seem to have been the case in this scenario, and I find that wrong.
It would be incredibly easy for me to financially abuse my elderly father or another elderly relative if I was that way inclined, because of the access that I have to their accounts etc. In light of this, I feel it is incumbent on me to ensure that everything I do is carefully documented and fully transparent so that my sibling and any other relatives can see exactly what I've done and why. I cannot imagine just helping myself to £100k even if my dad had explicitly told me to...I would insist on that being properly documented and witnessed.