Pics are hard to tell, but if it's clearcoat failure (which in certain parts it does), the only option you'll have is to repaint.
Compounds can only go so far in terms of reviving a faded finish, as you can't make a paint "darker" by polishing.
If it's oxidized, a heavy cut compound like Meguiar's 105 or 3M 36060 or even in a pinch Meguiar's Ultimate Compound from a local can do wonders. I dont usually recommend the last product as it doesnt have a lot of cut relatively speaking compared to the other two products, but is relatively easy to use without a multi-step polishing session. It contains Meguiar's patented SMAT abrasives which allow the user to compound without the usual heavy swirl marks which come after. A lighter polish after is still required but compared to products I've used, it does well on its own. There are compromises though, as a lot of the consumer-based products don't offer the aggressiveness of the "professional" dedicated products. I say "professional" as in products which are used in a bodyshop or pro detailing setting and not normally sold through retail chains like Walmart or Advance Auto. These options may or may not restore the finish without wetsanding.
In certain cases, I will wetsand first and then compound due to the time it'll take with a compound alone. I'll usually use a 3M Trizact 2000 (30666) or 3000 (02085) grit pad in combo with a handheld DA and go over the entire panel. Keep in mind, factory clearcoat is thin as hell so care must be used! Follow up with the 5000 grit pad (30662) to aid in the final buffing process. You can buff out 3000 grit swirl marks but it takes longer.
This is an option for experienced users only, and not something you should try and experiment on with a vehicle you value... Trust me, I know... I screwed up the hood of my mom's Lexus back when I thought I knew it all.
Lemme know if you have any questions, 16+ years in the business!
Cheers,
Rich
Edit: added parts numbers for sanding discs.