I'm not saying that EVERY excess death is due to COVID, but the vast majority of them are (67% through August 1, according to a JAMA study -
https://jamanetwork.com/journals/jama/fullarticle/2771761) and that's why the curve aligns so well with the initial spike in places like NY and NJ and subsequent spikes in places like FL. Also, in your example of someone dying from renal failure 20 days after a positive test, it's entirely possible or even likely that COVID-19 was the cause of the renal failure. If you mean that they already had the problem prior to contracting COVID-19, then it's still a possibility that the virus sped up the process - but it's also possible that this is a person who would fall under "expected deaths" calculations, since the CDC does take into account the typical number of deaths from various causes when determining how many deaths are expected. According to that JAMA article, there was a 3-week increase in expected deaths from heart disease (week ending 3/21 through the week ending 4/11) that coincided with the initial surge in the northeast. There was also an increase in deaths among dementia/Alzheimer's patients that coincided with the surge in FL (week ending 6/6 through week ending 7/25). Outside of that, there has been no statistically significant occurrence of excess deaths from any other causes.
In an interesting note, the authors state that excess deaths have been spread out longer in states that reopened earlier. As a comparison, I looked at the CDC charts for NJ and FL. NJ had excess deaths every week from the week ending 3/21 through the week ending 6/27. FL has had excess deaths every week from the week ending 4/18 through 9/26 (the most recent week listed is the week ended 10/3 and they state that recent weeks are incomplete due to delays in reporting).
In any event, there is no credible evidence that the death count is being inflated - especially intentionally - and credible evidence to suggest that it is NOT being inflated.