According to some quick googling I just did malaria kills around 600-700 thousand people per year, while in 2016 road traffic accidents killed around 1.3 million (both numbers attributed to the World Health Organisation).
Assuming that a majority of the road traffic deaths are attributable to humans then humans seem to very easily beat mosquitos/malaria at killing other humans.
You may be correct, I'm not sure. Apparently about half of humans ever have lived in the last 2000 years, and the death rate for those in the earlier half (before 2000 years ago) was overwhelming dominated by very high child mortality. I guess the answer probably depends on what proportion of those infant deaths were due to malaria.
Humans have already killed 600 million animals for meat this year and the year is only 4 days old. Humans aren't the only relevant creature on this planet.
