Paper blueprints" just gave me a flashback to graphite dust all over my hands. My old drafting pencil reminds me I could never draw a straight line, even with a ruler. Every one of my projects had at least one corner that looked chewed on. Frankly, the world is a better place now that my shaky hands can't ruin official plans anymore.
Manual drafting had so many tiny ways to mess up a drawing. Smudges and uneven pressure could ruin hours of work. Digital tools really saved us from that frustration.