FWIW: I started a blog/website on neocities.org a few months ago, and found some webcrawler blockers- at least a couple dozen there at the time, but they needed to be uncommented. So I am using them to block the various crawlers, presumably. I still have not put that to the test. By deactivating the blockers, and checking the site traffic states, one might be able to determine whether they are working or not. You might want to build a test site to try yourself. Neocities is free for up to one GB of space.

Years ago, I used google blogspot quite a bit. After every post was published, the first hit came from a server in Germany. Maybe a mirror or surveillance bot? I'll never know. But sure, it's a little spooky to be training AI with every post, and not knowing whose AI, and it's annoying to not be compensated. I've trained a lot of technical people over the years and it paid well. With the AI we get nothing.

Hey if you have enough interesting material, why not write a print book?

I cannot comment on the closed systems, as I have not used them, but I do think that WordPress is a viable option.

If you just want to write and for the writing to be seen by Google, then you really do not need more than a couple of plugins and you should have a working blog that you do not need to spend any time on maintaining.

I would go with GeneratePress - https://wordpress.org/themes/generatepress/ and its companion plugin GenerateBlocks - https://wordpress.org/plugins/generateblocks/ for some simple blocks to design the blog. Both of them are well-coded and fast/lightweight.

In addition to them I would use SEO Framework - https://wordpress.org/plugins/autodescription/ as the SEO plugin and you are set. Just set everything to auto update and there should not really be any issues.

No affiliation to any of those plugins/themes, but have been using GeneratePress, GenerateBlocks and GeneratePress Premium for years and not one update has broken anything for me.

What makes you think Medium and Sub stack articles aren't in Google? Medium ones are, for sure. I have a couple I've written that are top search results for their topic.

https://medium.com/@mimixco

Substack isn't invisible to Google. Not sure why you'd assume that.

WordPress is fine but if you want to primarily focus on content, try Ghost.org. I think their editor and design options are superior to WordPress.

I know, have been there. Another reason why i got a little away from substack is the trap towards vanity metrics sometimes. With notes etc its kind of becoming like a social media platform. It has its pros/cons. For some usecases, substack makes sense. But for my personal writing and more, i have been using bearblog which is amazing

You could always use ghost. You can still self-host it, but they have gone the direction of substack alternative these days.

I have been considering Ghost for these sorts of reasons. Pay for convenience knowing you can fall back to open source if needed.