So not that monetary incentives aren't part of the problem, but in addition to that it can also be hard to classify deaths sometimes and isn't always a straightforward thing. To take the example used, someone has HIV but dies of a heart attack. Well, anyone can have a heart attack, but (and I'm spitballing here) what if HIV makes you a higher risk? What if the meds you are on increase that risk? So now you technically died of a heart attack and that's what goes on the death certificate, but if you can blame the majority of your risk on HIV, can you say it's from HIV or not?
COVID causes a host of other problems that we know of, and testing isn't perfect. So if someone dies of a complication, it's going to be reported as a COVID related death even if that's not what goes on a death certificate (and to be clear, an infectious disease should NEVER be what's on the cause of death paperwork). But what if someone dies of a complication and has all the features of COVID but their swab was negative? What if they were positive before and got over it but it placed them at higher risk and caused other things to happen?
It's just another hugely grey area in a grey issue.