This depends on the tutorial, but I honestly believe there is very little learn from tutorials in the form of "how do draw x and y". This of course also depends on your goals, but anyone who's an aspiring illustrative artist should prioritize proper theory over step by step guides.
The difference is obviously, theory, in comparison to building up your visual library. The latter is by all means both good and necessary to practice, but is contradictory to use if your goal is to get better at drawing or painting. Improvement comes quicker and better from practice rather than copying, and if you spent time learning about theory, in an example, values, then the guide on how to paint an apple wouldn't be obsolete and useless when you later on decide to paint a banana instead.