There is absolutely still value in writing for its own sake. Personal blogs should first and foremost be for yourself. Long-form writing is a great skill and compiling your thoughts in one location is a great idea.

Not to mention that while you may not host the blog yourself, you will own the content. You can transport it anywhere, regardless of the shape of your blog.

As far as brand, finding readers and sharing content goes, I think plugging your blog posts here and there to your communities and social media platforms of choice is sufficient. Being algorithmically savvy about the process can be good, but posting to your favorite Discord server, your favorite social media network, and even just emailing/texting/DMs people works well too. Also... HN is good for this too, of course.