If I get to undercut your entire "HIV treatment" business AND line my pockets with your entire market share, then, good for me, bad for you. Sucks to suck. Should have cured HIV first if you didn't want me to do it.
There are many, many, many examples of "newer and better treatment X kills the market share of older and worse treatment Y" in the history of healthcare. Your conspiracy theory model predicts this never happening.
To counter, have you realized HIV is an evolutionary entity that is optimized to continue existing by not fucking dying. HIV mutates like crazy. I mean there are other things like the flu that mutate, but because we have partial immunity to the flu we can use that immunity to create new vaccines every year against it.
It doesn't take much self research to see that HIV is a rather insane virus, and if somehow out of the gate it would have been wildly contagious that it could have wiped humanity.
If your cynical take was correct, there would be no cures ever. And yet there are new ones all the time. For example, vaccines. There are way, way more vaccines developed in the 21st century than in the 250 years before that.
Vaccines against HPV have reduced incidence of cervical cancers to basically 0 in the cohorts that obtained them. How come? Shouldn't Big Cancer be interested in treating cervical cancers expensively and promoting relapses?
Even in cancers, your chances of surviving, say, Hodgkin's lymphoma, are now north of 90 per cent. The treatment is expensive, but time limited. You don't have to take pills for your entire life.
How does that square with your view of the medical system as a machine for prolonging diseases indefinitely?
If you're seriously sick you aren't making money because you can't work or all your money goes to Evil Pharma Co, then the Evil Government doesn't like that, because they can't wring taxes out of you. (Which they prefer since it's easier than fighting Evil Pharma Co.)
Meanwhile, The Shadow Government wants you to be healthy enough to work every day, or else they won't finish the navigation beacons for the alien invasion.