There's Google's blogspot, but that's not trendy. There's Wordpress, but that's not trendy. There are a host of blogging tools out there, but they're not trendy.

The question isn't what other simple platform is out there: the question is what blogging software do you want to be seen using. People don't want blogspot.com at the end of their domain names, and they don't want to look like they're using blogspot.com. They didn't mind Medium, and that's the difference. It's not a question of technology, which has existed for decades; it's a question of marketing and brands.

Several years ago static site generators were all the hotness. Around then I switched to Hugo [1] from Wordpress and it's been a good experience. I do all editing locally with the CLI then chuck it to Git to be built and hosted by Netlify.

[1] https://gohugo.io/

From the top of my head:

https://ghost.org/

https://writefreely.org/

I went back to mostly writing on my own website.