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.
Whether it’s generating CSS, javaScript or anything else, sooner or later you’re going to need something that the system doesn’t provide by default and so need to know how to amend or over-rule it.
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.
