There is no such thing as magic anything. Some of the friction reducing “magic in a bottle” stuff will do something. Many are chlorinated paraffins. What they do (maybe) is save you $6 for $25 in costs. Most are correct here in that the best thing that they do is clean your wallet.
There are additives that can be used to correct given issues, but without issue, there’s no reason to use them. One product that I used every 75k or so is Auto-Rx. It will clean long term deposits out of the ring area. Every used car purchased gets a treatment and all owned from new cars get it somewhere around 75k-80k. It’s also good for problematic engines or one acquired in an unclean state. The good thing about it is that it’s composed of 3 esters and isn’t $0.25 worth of solvent and $15 worth of marketing and advertising.