The UK NHS is chronically underfunded and far from perfect.
There is no doubt that mistakes do occur and some have serious consequences.
Every unnecessary death is of course a tragedy but just reading the headlines of the two links gives very different statistics:
Daily Mail: NHS (mistakes) causes 40,000 deaths a year
Independent: prescribing mixups contribute to 22,300 deaths a year
Further on the article, it says "The number of deaths where medication errors played a part ranged from anything between 1,700 to 22,303".
So which is correct? Probably the wording of the second article is more accurate whatever the statistics.
And would the unnecessary deaths across the entire population be higher or lower with the US health system?
This Wikipedia article
https://en.wikipedia.org/wiki/Gun_violence_in_the_United_States has data for total gun deaths in the US annually and comparative data for the US and other developed countries per 100,000 population.
US gun deaths were almost 40,000 in 2017 (taking both murder & suicide combined). Proportionately many times higher per capita in the US than elsewhere.
Any comments on my earlier analogies?
I think with both myself & CE now responding this could get very confusing
EDIT:
Per capita, if there are over 2100 deaths in the UK from medical negligence,
Where did 2100 come from? I guarantee there aren't 2100 deaths per capita!