Your paint is protected from oxidation by the UV stabilizers in the clear coat over the colour coat. So your focus should be on protecting the clear coat layer when performing paint maintenance. Washing your car frequently especially addressing contaminants (bird poop, bug guts, etc.) that can eat away at the clear coat can be more effective than choosing a sealant which rarely provides protection from these acidic elements. If you need true chemical resistance, consider getting a ceramic coating which is one of the main reasons for getting a ceramic coating other than self cleaning properties in rain.
Over an extended period of time even with proper maintenance, the UV stabilizers in the clear coat will start to breakdown which is your main protection from oxidation of the colour coat. Only Optimum Car Wax has lab tests to prove the ability to restore UV stabilizers in the clear coat (probably because Optimum owner and chemist, Dr. G was heavily involved in the development of modern clear coat paint). So consider using ONRWW which already contains Optimum Car Wax or consider periodically applying Optimum Car Wax after ONR.
You bring up an interesting point. I agree with some of the info in your post, but not all. A car paint's clear coat already contains all the protection your car needs from UV rays. The reason a car's paint suffers UV damage is due to the clear coat being damaged and/or dirty. So the key to preventing oxidation and other damage from UV rays is to keep the clear coat clean and protected.
1) It is true that Optimum was the first company to patent a car wax's UV protection capabilities and that they submitted lab results to back up their claims. However, this does not mean that Optimum's wax is the only wax on the market that protects car paint from UV rays. IMO many sealants and waxes provide some UV protection. I think Optimum's patent for UV protection is great for marketing and selling wax, but to say that you need to use Optimum wax or else any other wax will not protect your paint from UV rays is not true.
Mike Phillips, who is a well respected car detailing expert on Autogeek online once said this:
"Some waxes do contain UV-protection agents, but the amount of protection that a microscopically thin layer of wax can provide is limited.
The primary goal of a wax is to protect the top layers of paint that contain UV-protection agents from the paint manufacture. If you wash and wax your car regularly, your paint will be protected and you should suffer no major UV damage over the normal course of the life of the car.
Don't be fooled by some companies that lead you to believe that it is the UV protection in a wax that protects your car's finish from fading and failure, this is dishonest and simply not true. Taking care of the paint you presently have will go further to protect your finish than relying on protection supplied by a liquid you pour out of a bottle, or a wax you scoop out of a can. UV protection in a car wax formula is only an extra-dose of preventative maintenance, not the end-all, cure-all that some companies would lead you to believe."
2) Many paint sealants on the market today do indeed provide a very high level of protection against chemicals and contaminants. Yes, there are some sealants that provide very poor protection (for example Beadmaker, F11, Shine Armor) but many others provide very high levels of protection (for example The Last Coat 2.0, PolySeal, and even Turtle Wax Seal and Shine). Ceramic coatings are awesome, but they are not the only way to provide protection to your paint. The main advantage of ceramic coatings is that, although they do require some maintenance, they can last many years. Sealants, on the other hand, need to be reapplied every few months. But as long as you are consistent and diligent in reapplying the sealant, it will indeed protect your car.
3) It's interesting to take a closer look at Optimum's lab data submitted with their patent for the UV protection. Here is a quote from Dr G, the founder of Opitmum:
Dr. G stated: "The UV absorbers we use in the Optimum Car Wax are the same as those in the clearcoat paint. The testing we did is an ASTM standard test for automotive paint. A series of panels were painted with automotive base coat/clear coat at the Bayer polymer division (they supply isocyanates to the major OEM paint suppliers and some car manufacturers). The panels were placed in a QUV chamber for roughly 1,500 hours which is equivalent to 5-7 years of external UV exposure. As the test progressed, it was evident that the panels that had Optimum Car Wax with UV protection did not show any fading for the duration of the test while the panels without UV lost gloss and reflectivity (Definition of Image)."
I am not disputing the results. But the lab work is not without its possible flaws. Does the experiment really replicate real world conditions? What about road grime, contaminants, etc that are not introduced in a lab setting but would be in day to day use? And what about repeating the experiment but this time with other waxes and sealants?
Most ceramic coatings claim that they protect against UV damange. I don't know if it is the SiO2 that protects against UV or if there are additional UV blockers. But I would wonder if a ceramic-infused spray sealant would provide better UV protection than a sealant or wax without ceramic in it.