>HIV mutates so easily. I understand the basics behind how mRNA vaccines are generated, but I don't understand why this approach would be expected to have any more success in evading the high mutation potential of HIV than other vaccine types.

you buy not an mRNA vaccine shot, you buy subscription. We already getting a preview of it with the 3rd, 4th, ... Covid boosters. Allowing for cheap and fast vaccine development the mRNA tech is changing the business of vaccination. Add to that that in near future you'll be able to get personally customized mRNA vaccine. You'll just be getting your monthly/weekly vaccine subscription box. And why limit to vaccines? The mRNA can make your cells produce any protein. Imagine a subscription business possible here.