Let us say that you want to analyze, say, drinking culture in Ireland. You could write documentary on it, or do a fictional character study. However, those require actors, camera equipment, editing tools and time, and it generally extremely expensive and time consuming. A quick TikTok video may be a bit cheaper than a full-scale film, but still needs some of that equipment and cinematography skills.
Music is not much better. You need skills in singing, translating ideas of rhythmic lyrics, as well as supplies for instruments.
Writing, however, is simple. At minimum, all you need is paper and skill in articulating ideas. Almost anyone worthy to rationally ponder a topic already has the skills to put it to paper (assuming that they have gone through a proper First-World education and know reading and writing).
Text is also one of the easiest to share. A picture is worth a thousand words, but that poses problems in sending all that information. Plain text, however (or even most rich-text formats) can be transferred to anyone over almost any protocol, even rudimentary ones such as word-of-mouth. Ideas shared through text can be sent at an unrivaled pace.
500 Internal Server Error