Over the many years I have been developing websites few advancements have beaten the change from css to pre-processors such as sass and less.
In the good old bad old days css was highly labour intensive and could often involve hours of repetitive tasks.
With the advent of pre-processors variables and snippets have made modular style css structures a massive improvement.
Couple that with the stunning frameworks of bootstrap and foundation things are really in a good place.
Certainly newbies won’t have to endure any of the table driven browser wars from the IE and Netscape days.
I just wish I had enough time to experiment and explore.