Are you an experienced developer? Do you use open source software on the daily? If you don't have a blog you're doing a disservice not only to the community, but to yourself as well.
To be clear, by "blog" I don't mean that you need to have something which you need to consistently take time out of your week to write down. I'm talking about things that you will be jotting down in personal notes, or keeping in your memory anyway.
If YOU are going to need that information in the future, someone else might just need it too. So why not share it with the public in the form of a blog? It's better than putting it somewhere else and losing it altogether, isn't it?
I found a great example of this today, an article by Amos from 9 years ago, on how to use ooc for cross platform game distribution. It covers many details that you would need to set up your build environment that could otherwise take weeks to figure out by yourself.
It reminded me of my first ever blogpost, which I wrote after painstakingly figuring out how to setup postgres on my distro.
Learned something about a library that isn't clearly mentioned in its documentation? Write it down. Figured out some tricky steps in setting up a project? Write it down. Anything else that you had to spend a considerable time to get working, just write it down. Not only will it help you in the future, it might just help a newcomer enough to avoid them quitting their passion project.
Write it down.
P.S. If you don't want to spend time customizing your own blog, use a hugo template, they're really easy to setup. If you don't want to care about hosting, domains, or anything else, dev.to will do all of it for you. It doesn't really matter where, as long as you write it down.