only a fraction out of every mosquito species actually spread disease. they make up a bit of the biomass in the arctic regions iirc and some birds even eat them as part of their diet.
scientists have been experimenting with mosquitoes, trying to find ways to uninfect them/rid them of their diseases
I haven't been bitten in a few years. I go nuclear. Fogger, torches, candles, spiral things, bug zapper and a bug zapper tennis racket thing. Oh and bug spray. And I grow plants around the deck that repel bugs