Hopefully this will work out - but it's still early days to be sure if this really is a cure, as the article explains. Some scientists believe that there will never be a cure - hopefully they will be proved wrong. If a cure is found, this will of course be cause for great celebration. Bringing that cure to Africa and other poor regions will be a mammoth task.
It's taking them so long because HIV is a very crafty virus which hides in very small quantities in places which are very hard to find, even when the body appears to be rid of the infection.
But remember that a "functional cure" became available in 1996, when the first HAART drugs became available, and people who were basically on their death bed were brought back to life. This was still five years too late for Freddie however - so that idea which is sometimes brought forward that had he pulled through for "some more time", he might have been saved, is fallacious I think - he'd need to have lasted five whole years more.