I don't work with webgl much but I remember there being a max texture size of around 2048 or 4096 on many devices. Wouldn't you end up needing to tile the texture and stuff?
There is a limit on canvas size in most browsers, unfortunately it's rather low on iOS, more than 12 megapixels (4000x3000) will result in empty canvas elements.
Indeed progressively loading high res textures or tiling is a solution to this.
Indeed progressively loading high res textures or tiling is a solution to this.