I don't think one can assume that mobile devices have bandwidth problems the majority of the time anymore. mobile/iPad users utilize their devices while on wifi at least 50-70% of the time I would guess ( in my case, closer to 95%) so bandwidth is no more an issue during these times than on a desktop. I agree that using LTE, 3G or 4G might be slower, but wifi is universally available to many users, and with options like lazy loading. of images, etc., it is much less an issue. Just my 2 cents.