The end-user internet connection speed is still to be taken into account.
Once again, when I went to the site of a popular social network, I was once again surprised by its slowness on a regular cellular modem.
It is worth the modem to switch from 3G to EDGE (the tower is overloaded or something else), as everything starts working through the stump-deck. I'm not talking about videos from Youtube or downloading files, even JavaScript on some sites refuses. Pages of some sites that carry about two printed pages of useful text and a couple of pictures manage to “weigh” 1.5 MB each (downloading via a cellular modem takes 20 seconds). But the work through a cellular modem or mobile phone for modern reality is an ordinary case.
It's amazing how many sites are not ready for such a reality!