I believe you will find that not to be the case today but it depends on your application. Build the pages, optimize as needed for
your audience and you should be just fine. Here in Central America we must be overly conservative because the internet flows through molasses between machines! A couple of years ago 30 kbps was common here.
On the other hand, javascript libraries can be very large and that can be an issue. Take a look at the article and comments linked below.
Condensed Javascript