A thread disappears in a day. A post in a feed is gone by the afternoon. The ideas you spent real time shaping deserve better than a format designed to be forgotten.
Writing is one of the highest-leverage things an independent professional can do. It demonstrates how you think, it earns trust before a conversation ever starts, and it keeps working long after you publish. But only if it has somewhere permanent to live.
Make it accumulate
When every piece lands on your own domain, your work stops being disposable and starts compounding. Each post adds to a body of thought that people can read, cite, and return to. The archive becomes part of your professional identity.
That is the case for a permanent home. Not to write more, but to make sure what you write actually lasts.