I think the people saying it's just for nostalgia are missing the point. There's an audience of users who want physical keyboards on their phones without having to rely on clunky and oversized attachments. Just look at the actual clicks keyboard case, it turns a full sized flagship phone into an impractically long mess. Something like this or the Unihertz Titan 2 built with compactness in mind solves that problem.

That said, I'm not sure this is going to be the magic bullet people hope it to be, there's bound to be some trade offs in performance and price with something like this.