I'm pretty sure they're compressing videos to save space on server, otherwise they should spend a fortune to keep all these videos up there.
I don't care about fps, my eyes are happy with 30 fps that is how much they could get (if I remember well) and I don't mind if I can't catch the sight of specks of dust. I have no pay TV and want to enjoy some rally looking at live stages, onboards, highlights and interactive maps. wrc+ give me this for 30€/yr and as long as it works it makes me happy.