Oil additives in general has many uses. So the question is rather what specific mix they are trying to sell you and for what reason. And of course, if that is something you need.
When it comes to your average consumer vehicle it is not as important. Oil is definitely a important part of it all but at the same time consumer vehicles are created with such wide tolerances that you can run it on pretty much anything and it wont explode. Rather than looking at additives it would be better to just keep up with regular maintenance. Oil and filter change as well as what else is listed as services for the vehicle you have will make a far greater change than a additive will.
For anyone with experience of high powered machines, racing machines for example, will know that regular oil changes and clean filters will save you much more than fancy oil or extra additives ever will.
As oil degrades many things can happen, it can become acidic and corrode the engine from the inside, fill up with particles and other impurities that can cause damage. Or degrade to the point where it no longer lubricates well.
But generally speaking, anything that just says it would increase power, extend oil change intervals, cleans and all that in one singular product for apparently _all_ machines, is most likely not worth considering.
Oil that you buy for vehicles is normally already mixed in a similar fashion, part oil and part additives to create the specific oil being sold. Adding another part additives to said oil might not always be the best of ideas without knowing what it will do or a specific reason to doing it to start with.
So yeah, it probably has all the additives normally used to balance viscosity, lubricity, corrosion resistant, detergents and the like that is used for what they say it will. But as always there is very little information to find about actual tests done and numbers to look at. Just a sellers claims that its the best thing since sliced cheese.
If it was my choice, I would rather just change my oil than rely on supplying a new mix of additives to already used oil. And if your adding additives to brand new oil its kinda pointless, since oil used for motors, gearboxes and the like already come mixed with additives for that specific area of use. So it already have additives for correct viscosity and lubricity etc. and here you come adding more additives for the exact same purpose.
The main reason these products exist is probably because the average person neglects their service intervals regularly in which case new additives in used oil where the additives may have degraded can be of use. But you don't know that without checking the oil first. And of course people will just buy it, use it and say it "worked" even though it may in reality not have done anything helpful at all. I mean I seen vehicles that haven't had their oil changed in decades and they still work, so there isnt all that much useful information about how well the product actually works.
There is a lot to read up on when it comes to oil used for engines and there are many aspects to consider when creating a mixture of oil to be used. There are many kinds of additives used for many different reasons and they can change widely depending on vehicle of choice, how it is used and where it is used.
And the only way to ever know is to have it properly tested and such testing is few and far between these days.