Cool. Regardless, my point stands: this is a mainstream image format today (as others have pointed out, Google, Facebook and Twitter drive somewhere close to half the web and use it), and that ratio will only grow.
Photoshop doesn't support it? Is the point of Affinity Photo to be as good as Photoshop, or better?
I don't understand the arguments against supporting WebP at all. Is it the work involved? It's not a lot of work, open source libs for WebP are commonplace. Are they secretly hoping that WebP will fail in favor of superior, patent-free formats? I've been waiting twenty years for that, good luck.