The Aedes spp. mosquitos contribute negligently to the food chain. In most areas with dengue they are invasive species. They are almost entirely urban species that invaded those spaces. Lastly, there are dozens of mosquito species that do not vector human pathogens and are going to continue existing in the environment.

All that said, I think there are better ways for governments to spend their money to fight vector borne diseases.

“Aedes aegypti originated in Africa and was spread to the New World through slave trade,[15] but is now found in tropical, subtropical and temperate regions[16] throughout the world.[17]Ae. aegypti's distribution has increased in the past two to three decades worldwide, and it is considered to be among the most widespread mosquito species”

Do you really think that scientists haven’t done an analysis on the global food chain?

Mosquitoes contribute almost nothing to it and their costs outweigh any benefits.