Another data point:
Plat Charge, had the card for 2 years with maybe $3-4k spend per month, annual fee charged last week. Called around 3pm AEDT today, sounded like it was answered in the Philippines. Selected 'Card cancellations' from the voice menu, and advised operator I wanted to cancel the card as AF charged last week, less benefits now (eg. KF and concierge), etc. She asked me to confirm if I wanted to cancel the card due to having less benefits, which I confirmed I did. She asked if I made use of the other benefits, which I said I had but am now paying the same fee for less benefits. I asked if they could discount the AF due to less benefits now. She didn't answer that, but straight away offered 70k points if I kept the card open, which I accepted.
Obviously others have had higher but others nothing at all, and I don't put a heap of spend on mine, so overall quite happy.