I believe at this point prevention is better than cure , especially since there is no cure. Money NEEDS to be spent on education before anything right now.
Prevention is already being done but unfortunately people just don't understand or don't care. When they say that 15% of all people have tinnitus most people go: "Well that's a really small chance. 85% don't ever get it. I'll be fine, no need to wear earplugs.". On some festivals and concerts here in Sweden earplugs are handed out for free and still pretty much nobody wears them.
Just look at something like HIV. There isn't a single adult in the West, and probably in most other parts of the world as well, that doesn't know about STD:s and HIV. HIV was literally a death sentence until not so long ago. AND STILL many people refused to put on a condom! Good luck getting them to plug their ears...
The only prevention that might work is to legislate that no earphones, headphones, speakers or any venue should be allowed to generate harmful noise levels (>85db). But good luck with that too...