Branding is the culmination of all marketing efforts and it is what the consumer sees. Therefore, if branding fails than all of marketing strategies hind building the brand are flawed. Therefore, there is more interest on branding by both practitioners and researchers. Further, some of the leading journal editors seem to engage with branding literature.
I don't know if the interest in brands is actually increasing. Do you have a meta study available? It is of course true that "brand" is a central field of investigation for a lot of researchers. An indication of the brand's importance may be the brand values, e. g. on interbrand.com in relation to the corporate value. The problem of calculating the brand values must of course be taken into account. Nevertheless, they provide an indication of the significance of the brand for companies and an indication of its relevance to business administration.
It does not seem to me that the interest in branding have been increasing. However, for sure we would need to find some kind of survey related to the action that marketing managers have been dealing with. Brands always call attention because in a way or another they are in the center of marketing communication. On the other hand, we would need a kind of bibliometric study to have an idea if the interests of scholars on the subject have been increasing. If we look at the journals which are published in the field, as for instance, Journal of Brand Management, Journal of Product & Brand Management, and Journal of Brand Strategy, among others, brand, of course, will be a trend topic.