Caused by the initial shock of AIDS, and ongoing activism, there has been consistent funding from federal and various private sources in development. Thanks to these efforts, antiretrovirals are widely available, making AIDS a "solved" problem in the sense that you can prevent AIDS onset indefinitely with the right medication.

Right now, the problem is more about actually accessing the people who might have HIV, getting them to test themselves regularly, and then giving them access to HIV medication if they are positive. Often these people are on the fringes of society. A vaccine would be an ideal tool to reach these people than asking them to get tested regularly.

HIV is a way harder virus to develop a vaccine for than SARS-CoV-2. For starters, once you have it, HIV is way more dangerous. Most people with covid don't need medical attention at all, they can deal with it themselves. Meanwhile, someone infected with HIV is basically sentenced to death in a couple of years if they aren't medicated (>90% mortality rate). The current covid pandemic is so severe because covid spreads so much better than HIV does. Our immune system can't really deal with HIV in a way that we survive the encounter. With SARS-CoV-2 you only need to slightly nudge the immune system into the right direction. That's a way easier task.

HIV also has an immensely large mutation rate. The genetic diversity in a single individual is larger than the genetic diversity of one entire yearly influenza outbreak. So you need to come up with defenses that help against a gigantic set of HIV viruses. We still need to vaccinate people yearly with an influenza shot, because we can't create universal influenza vaccines yet. It's an open problem similar to how a HIV vaccine is an open problem.

TLDR: There is already something like warp speed for HIV, but we were mostly lucky that it was so easy to come up with a covid vaccine.