Right. The server can immediately know all the files that the client could need (and with some coordination.. does need). The client though has to get the first one to learn what others it may need, then request those.. and those may require more. Each level of recursion costs you at least 1 round-trip latency, likely much more due to the links not being at the very top of the page, the server not being instantly fast, and the browser's rules for requesting things.
