For years SEO counted links. Mentions without a link also carry information: a brand named next to a city and a trade, in reviews, in press, in forums, tells an engine what the brand does and where. Google has described using mentions to build its understanding of entities, and AI assistants write answers from exactly this kind of text.
Earning mentions means being present where a trade is discussed: directories, client reviews, interviews, case studies published by clients, comparisons. A consistent description of the company everywhere (same name, same city, same speciality) makes those mentions add up instead of scattering.