Hand coded markup is still essential. Preprocessors, frameworks and libraries are there to make your lives easier, but they are not intended to replace coding skills.
Using systems like these to make coding easier or repetitive tasks quicker, makes a lot of sense. However, over-reliance on these systems can be risky.
Also bare in mind that things like jQuery require a sizeable initial download, so if you’re only using it for a couple of simple behaviours it’s worth knowing how to write them yourself instead.