I completely agree with you. When it comes to academic writing, the content transforms itself into a more coherent entity as I write. Oftentimes the big picture seems laughably inadequate and even inaccurate when I look at the final product, so much so that writing itself seems like research and thinking beforehand, almost redundant.

Hamming agrees in his famous speech (see the Q&A section on this page - https://www.cs.virginia.edu/~robins/YouAndYourResearch.html) that 50% of the time is just spent writing/presenting research.