[maxk42]

According to WordPress, it's about 25%. [1] So it would mostly be not-WordPress.

[1] https://venturebeat.com/2015/11/08/wordpress-now-powers-25-o...

[liveoneggs]

that is out of date- wordpress is up to over 33% of the web

https://wordpress.org/news/2019/03/one-third-of-the-web/

That's the entire web. It is staggering.