Activity doesn’t equal productivity.
What you do and what order you do it in matters.
Here are two simple heuristics to help determine both:
To determine what, consult your values: what do you care about the most really?
To determine order, consult time: what will matter in the long run? Prioritize those things first.
None of this is essential, of course — it just depends on how much serendipity you’re willing to tolerate.