Not only for drawing and writing! Having plenty of paper on hand means you have instant access to a host of creative activities. Paper aeroplanes, and other fold-up games like a paper fortune-teller, are always appreciated and help small hands develop fine-motor precision and strength as well as introducing early ideas around maths and science (how far will your plane fly? When will it drop?).
You can also use tracing paper for pencil control (for better handwriting), strong paper for rolling up to make a telescope or a trumpet, sugar-paper for flowers and decorating hats, and regular paper for writing letters to Father Christmas. Cut it up and make garlands or window stencils. Use printouts you no longer need to cut out letters or words, keep envelopes with windows in to make a frosty winter scene. The possibilities with paper are endless. And best of all it can all be recycled at the end of the day.
