I agree with @pir. 'Incumbent' is not the right word to use in this context. The non-native writer has found this word in a dictionary and used it inappropriately. I'd presume that they mean 'present' or 'current'.

In this context the most likely meaning is "current", but native speakers wouldn't use "incumbent" there. I suspect the writer was not a native speaker and got it from a dictionary. They're also using the wrong preposition at the end; it should be: "more economical for the customer".

it means that the product that is talked about but not named, is better then the one commonly used. in·cum·bent inˈkəmbənt/Submit adjective 1. necessary for (someone) as a duty or responsibility. "it is incumbent on all decent people to concentrate on destroying this evil" synonyms: necessary for one to, essential that, required that, imperative that; More 2. (of an official or regime) currently holding office. "the incumbent president had been defeated" synonyms: current, present, in office, in power; reigning "the incumbent president" noun 1. the holder of an office or post. synonyms: holder, bearer, occupant "the first incumbent of the post" it is referring to whatever product that is not named, but that is dominating the market, but inferior the new product" the "your product" hope that makes sense