It’s pretty. By default, even. Floorp is customizable, but many (most) people want a tool that works directly out of the box, and if it looks good while doing it, then it will be more popular.

The dev advertised it on Reddit, then when people complained about issues, you would see a response from them along the lines of “fixed,” which showed responsiveness, and I think that gained loyalty before the product was ready to be released.