The smoke and smog from those engines and appliances directly kill nine million people a year
In 2020, fossil-fuel pollution killed three times as many people as COVID-19 did.
The otherDan Romik's answer does a good job of critiquing the 9 million people per year, but the other side of the equation is also uncertain, as in did only 3 million people die of COVID-19 in 2020? Studies have tried to estimate the true death toll of the COVID-19 pandemic and they come up with an answer that is many times higher than the official one. Nature discusses two models that attempt to use excess mortality to estimate the true death toll, and the answers are about three times greater than the reported deaths:
Another challenge to the official numbers has recently been published, though at time of writing this is currently only available as a non-peer reviewed pre-print, is an analysis of nasopharyngeal swab taken from 1,118 deceased individuals at a single hospital in Lusaka, Zambia. The detected COVID-19 was detected among 32.0% of those samples. During times of peak transmission COVID-19 was detected in ∼90% of all deaths. This indicates that only about 10% of COVID-19+ deaths were identified in life, indicating an under-counting of approximately an order of magnitude. This is consistent with a surprisingly low incidence of reported COVID across much of Africa and may indicate the true death toll is many times that reported.
While there is plenty of uncertainty in both these figures, andanalyses. In the former there are semantic questions about how deaths indirectly related to covid are counted in this context. In the latter is very hard to generalise to wider situations than this hospital and would be expected to be very different in areas with more testing capacity, which probably means most of the world outside of Africa. However considering both these areas of uncertainty assuming that only 3 million people died from COVID-19 in 2020 is not reallywell supported by the evidence.