I think the terminology you are looking for is called "Deliberate Practice" (just two random links I just found). Many books/podcasts/articles have been written about that topic. The big difference is when you "just do your research" you are executing your skills and trying to achieve the main goal (e.g. answering a research question). Yes, you sometimes need to read textbooks or learn new skills to achieve that, but this learning is usually subordinate to your end goal. Also one could make the argument that if you actually need to invest a few hours into learning, you will probably switch to "deliberate practice mode".
Deliberate practice is the very intentional action of improving your skill, e.g. sitting down on a piano and improving your technique, learning a new piece. Or improving as a writer by doing intentional exercises, or solving specific math problems that improve a certain skill.
The advantage of deliberate practice is that its main goal is to improve your skill. Also usually you are at the edge of your ability, pushing through difficulties, making the whole endeavor very intense and hard.
So yes, I agree that doing research is important. Especially if you have no experience then getting better at research is usually best done by doing research. However, you still need to do other things that specifically improve subskills. Here are a few examples:
- become better at coding: e.g. through paired programming, coding reviews, Hacker Rank exercises, side projects, reading books
- becoming better at writing: e.g. doing writing exercises (no idea what exactly but I'm sure there's stuff out there), reviewing stuff you have written, trying to imitate the style of a paper, writing blog posts
- becoming better at reading papers: reading lots of papers, summarizing them, presenting them, writing a blog post about them
- becoming better at finding good research ideas and being a good researcher: talking to lots of people, reading lots about researchers' thoughts, Film study for research, etc.
I think by adding terminology I just wanted to make explicit what you mention in your post. It will also make it easier to find resources given the word "deliberate practice".