i am under the impression that mosquitos, as an invasive species, do not fill an important ecological niche and could go extinct and be replaced by other insects
This has been a common sentiment but it hasn’t been proven in any substantial way to my knowledge. I personally doubt it’s accurate. That’s not to say the entire ecosystem would collapse but there would likely be consequences.
That said, the other commenter is correct that there are many introduced mosquito species that could probably be eradicated from their non-native range without major ecological harm. And the species that are the worst pests in human cities tend to be introduced, so eliminating them might significantly reduce the level of bites and disease transmission for people.