Whether you work in design,
Comparative advertising has been defined by Wikipedia to be an advertisement in which a particular product, or service, specifically mentions a competitor by name for the express purpose of showing why the competitor is inferior to the product naming it. It is different from parody advertisement, where a non existing product gets advertised to be made fun of.
Comparative advertising is generally related to negativity and various stories have linked this form of advertising as having a negative impact on the brand and its conception to consumers.
Take for example the recent Patanjali ad campaigns attacking Lux, Pears and Lifebouy soaps. They’ve been injuncted by the High Court.
Their ad campaigns were laced with negativity and could have a negative impact on their brand image. Asking people not to use chemical infused soaps like the celebrities and edging people to stay away from certain brands.
This hitting below the belt advertising should be used as last resort or not at all.