A more deadly virus, as we saw with SARS, was that it was actually easier to control because the high death rate made it very easy to contact trace and identify infected.
In many ways covid19 is a challenge exactly because it doesnt kill too many people.
HIV is extremely deadly without treatment, but has an asymptomatic stage that can last over a decade despite still being infectious during that time.
The silver lining with HIV is that its modality of transmission is primarily sex and blood, which greatly limits the number of contacts an infected individual will have.
An airborne disease with the lethality, incubation length of infectivity, and vaccine resistance of HIV would be a slow moving disaster of an unimaginable magnitude.
I am not aware of any theoretical reason such a disease cannot exist.
And yes, malaria is not discussed enough. I remember Bill Gates releasing mosquitos in a room before a speech to get the public attention "these could carry a deadly disease we have no cure for"